318 Build.. Zero Deck or Stock Deck Clearance?

[MOPAROFFICIAL]

I'm glad you and 72bluNblu mentioned this. I had no idea the KB 167 has a required ring gap. Didn't look for a spec or info sheet before I sent them to the machine shop for the the boring to be done. The The problem with decking the block and why I was asking, was the machine shop my block is at right now does not assemble anything and will not do the deck clearance measurements. I would have to get it back to my house, measure it and then send it back. I found another machine shop that will do the measurements and deck it, but that was just extra money and a day off work. Which I really did not want to do that to make sure I had days for The Nationals in August, and in case life happened and I needed days for whatever reason. I plan to measure the clearance when I get the block back to see where it is at then make a decision. If the clearances are close in both banks I may not mess with it being it will primarily be a street car and just use a thinner head gasket to make a little of the difference up.

If you don't have the cash to pay a shop to measure and cut appropriately, I'm thinking you don't have and accurate way to measure deck height at each corner.
If you start thinking you're over your head, just have it cut .004 and call it good.
If you do and can, even better.
Now I hate to see people argue over what you should do with your motor, and honestly for the most part, and overall, it will run fine if you decide not to run it zero deck...however, it would be a complete and utter lie to say it wouldn't run a lttle better & have 'more torque at all rpms' if you do zero deck it and run a higher 8.5-8.6 dynamic 91 octane...you would also be running less total timing due to a faster burn as well, that might make a smidge more mileage. Either way, people shouldn't get into it with eachother over it. Good luck.

 

[MOPAROFFICIAL]

With iron heads?

Yes, J heads, milled to 60 cc. Shallow side of chamber is .029-.030, quench head pistons milled to take up the head gasket/come flush with compressed head gasket . Cranks 185 psi total timing 28 w/20 initial. Starts up like now, no run on.

 

[AJ/FormS]

And to me one of the most important things is to nail down the ICA first. Cuz if you close the intake too soon, or too late, with the compression already written in iron, well then you may be stuck running more expensive gas than necessary,to get the octane the engine wants, or running more gas through the combo, cuz the hole at tip-in needs 4.10s to be liveable.
I learned that the hard way. I'd rather have to buy gas one grade higher, than live with the hole or run 4.30s.
But There is another way; Build the engine for tightQ, whether zero-deck and .039 gasket. or 010 down and 028 gasket. Either way. Finalize your Scr. Then select a cam with the correct ICA to work with gas you want to run. If it ends up that you have to run a bigger cam than you wanted to,to get a handle on the Dcr, well there are still ways to deal with that(within limits,of course). If the Scr comes in too low and you have to run a teensey cam to keep the Dcr up, now that is a problem. But highly unlikely , in this case,heehee.Cuz the OP wants to run a 280H!

 

[AJ/FormS]

Quench is your friend...especially if its tight , like .030. .*Smoothing any sharp edges helps as well*
I run 10.1 static & 8.8 dynamic on 91 octane with .030 quench.

If you don't have the cash to pay a shop to measure and cut appropriately, I'm thinking you don't have and accurate way to measure deck height at each corner.
If you start thinking you're over your head, just have it cut .004 and call it good.
If you do and can, even better.
Now I hate to see people argue over what you should do with your motor, and honestly for the most part and overall it will run fine if toy decide not to run it zero deck, however it would be a complete and utter lie to say it wouldn't run a lttle better, make a little more torque at all rpms if you do zero deck it and run a higher 8.5-8.6 dynamic 91 octane...you would also be running less total timing due to a faster burn as well, that might make a smidge more mileage. Either way, people shouldn't get into it with eachother over it. Good luck.

Yes, J heads, milled to 60 cc. Shallow side of chamber is .029-.030, quench head pistons milled to take up the head gasket/come flush with compressed head gasket . Cranks 185 psi total timing 28 w/20 initial. Starts up like now, no run on.

See, Here is your recipe!This is the best data of all; realworld.
10.1/8.8/.029Quench/185psi/91gas/28&20timing

So let's run that 280H. I found this cam; 10-204-4 with 280/280/110/230/230 &490/490lift Thats a lot of cam for a street teener but here goes.
If you install it at 106, the ICA will be around 66*. Using a bore of 3.94,stroke of 3.31,rod of 6.123, This cam wants an SCR of 10.5 for a Dcr of 8.23 and 166psi.This is what typically burns 93 with a tight Q.To get a 10.5 Scr you need 69.6cc total chamber volume.
Anybody see a problem here?
Ok lets say the heads do come in at 59, and the gasket is 8.9 and the eyebrows are 5 and say the pistons are down .010=2cc. Ok; 59+8.9+5+2=74.9cc Winner we have a dog-motor!
Well not really, the Scr works out to 9.8, and the Dcr to 7.7/152psi. So it will have a hole, need a big TC, and gears and suck gas pretty good around town, exactly wrong for a streeter.
In this case you would need to eliminate 5.3cc to be rocking. Well there are 2 in the deck height, which are very expensive to buy. But you could go from the .039 gasket to an .028 and get 2.5cc there. Your Q would be better at .038, and the compressions would climb to 10.13/7.95/159psi. And that is much better.
But really that cam is 230@050, kindof way too big, IMO,for a street-teener.And it's a single pattern cam.

Now, if you would be willing to to go down to say a 270 cam and install it at 108 the ICA might come in at 63* and then that 9.8 engine would get you a Dcr of 7.9@157psi. This is still a pretty big cam for a teener.
With the 10.13 engine this would be Scr of 8.14@164, yummy!

And if you would consider a 262 cam and the 10.13Scr, you could get you an ICA of 61*, and a Dcr of 8.25@166psi. This is dynomite! This will boil your 275s a good long ways.It will get fabulous mileage. It can use the stock 2200ish TC, with 3.55s.If you need a lil more Giddy-up, a 2800TC will really wake it up, and that 2800 might work pretty good with 3.23s if they are already in there.
So to recap, this is pistons down .010, the .028 gasket, and 59cc heads.

Now I'm not telling you to run the 262 cam. I'm just having fun with math....... You can change the parameters any way you want to run almost any street cam, some combos just look better on paper. Measure,measure,measure. That's the difference between a Fantastic engine, and an also-ran.
>Pressures over 165 usually need 89 to 91 gas under load. But with a TightQ , moparofficial says he runs 185. I can't say one way or another, and to you it doesn't matter, cuz your heads are chosen, and there is no way to get your total chamber volume down low enough to get that much pressure with any performance cam.Well there is but that would take custom pistons.
As for me, I'm liking the 270 with a 2800 and 3.73s

If it helps any, I have run a totally stock low-C teener long block with a 2800,3.55s,the 2.74low A999, headers, and a TQ,in a 3650 chassis, and I had a lot of fun with that. Almost as much as when I ran it with 4.30s and a 4-speed. Actually I think I mighta had more fun with the automatic.

 

[MOPAROFFICIAL]

See, Here is your recipe!This is the best data of all; realworld.
10.1/8.8/.029Quench/185psi/91gas/28&20timing

So let's run that 280H. I found this cam; 10-204-4 with 280/280/110/230/230 &490/490lift Thats a lot of cam for a street teener but here goes

Something with 50 closing. With Wallace I get 9.78 static.., zero deck, 60cc head,5cc relief, 8553 .046 compressed 4.180 gasket, 3.31 stroke, 3.94 bore.
50 ivc w/9.78 ....8.46/172 cranking.

 

[mopowers]

Excellent point, thanks for bringing that up. The hypereutectic pistons require a specific ring end gap, and deviating from that spec can and has caused those pistons to fail. They're good pistons but you MUST use the specified ring gap because of the metallurgy of the piston.

I always thought KB pistons required larger ring gaps because the ring lands were higher and therefore got hotter. I had no idea it was because of the material difference itself.

 

[72bluNblu]

I always thought KB pistons required larger ring gaps because the ring lands were higher and therefore got hotter. I had no idea it was because of the material difference itself.

Hyper pistons reflect more heat, therefore putting more heat into the chamber and running the top ring hotter. So, the upper ring gap is larger. But, the piston itself expands less because of it's improved thermal conductivity, so you also run tighter piston to cylinder clearances.

Here's some of the specs
#2---- Clearance Requirements for Hypereutectic Pistons

Chart is originally from United Engine & Machine Co. Incorporated, Performance Pistons

 

[mopowers]

Hyper pistons reflect more heat, therefore putting more heat into the chamber and running the top ring hotter. So, the upper ring gap is larger. But, the piston itself expands less because of it's improved thermal conductivity, so you also run tighter piston to cylinder clearances.

Here's some of the specs
#2---- Clearance Requirements for Hypereutectic Pistons

So it sounds like it's a combination of factors. Ya learn something everyday.

 

[RustyRatRod]

If he decks the block for zero deck height, he will have more compression, but because he will have perfect quench, it will not detonate. With the magnum heads and zero deck and flat tops, he could probably approach or even eclipse 11:1 before he had to worry. So he's plenty safe.

He asked about compression, so I answered that he is at the compression already that will be challenged by todays gas. In other words, he doesn't need to "deck" the block to gain compression, IF all he is after is compression. His compression with those heads and pistons will be more than adequate for a street engine, no matter if his pistons end up .010 in the hole, or .040 in the hole.
AND...... AND..... the compression will be more than sufficient to perform.

 

[AJ/FormS]

If you decide to go for the zero deck, make sure you are confident that your machine shop can do this right. If your block comes back all messed up, you are gonna be one very unhappy camper.

 

[MOPAROFFICIAL]

See, Here is your recipe!This is the best data of all; realworld.
10.1/8.8/.029Quench/185psi/91gas/28&20timing

So let's run that 280H. I found this cam; 10-204-4 with 280/280/110/230/230 &490/490lift Thats a lot of cam for a street teener but here goes.
If you install it at 106, the ICA will be around 66*. Using a bore of 3.94,stroke of 3.31,rod of 6.123, This cam wants an SCR of 10.5 for a Dcr of 8.23 and 166psi.This is what typically burns 93 with a tight Q.To get a 10.5 Scr you need 69.6cc total chamber volume.
Anybody see a problem here?
Ok lets say the heads do come in at 59, and the gasket is 8.9 and the eyebrows are 5 and say the pistons are down .010=2cc. Ok; 59+8.9+5+2=74.9cc Winner we have a dog-motor!
Well not really, the Scr works out to 9.8, and the Dcr to 7.7/152psi. So it will have a hole, need a big TC, and gears and suck gas pretty good around town, exactly wrong for a streeter.
In this case you would need to eliminate 5.3cc to be rocking. Well there are 2 in the deck height, which are very expensive to buy. But you could go from the .039 gasket to an .028 and get 2.5cc there. Your Q would be better at .038, and the compressions would climb to 10.13/7.95/159psi. And that is much better.
But really that cam is 230@050, kindof way too big, IMO,for a street-teener.And it's a single pattern cam.

Now, if you would be willing to to go down to say a 270 cam and install it at 108 the ICA might come in at 63* and then that 9.8 engine would get you a Dcr of 7.9@157psi. This is still a pretty big cam for a teener.
With the 10.13 engine this would be Scr of 8.14@164, yummy!

And if you would consider a 262 cam and the 10.13Scr, you could get you an ICA of 61*, and a Dcr of 8.25@166psi. This is dynomite! This will boil your 275s a good long ways.It will get fabulous mileage. It can use the stock 2200ish TC, with 3.55s.If you need a lil more Giddy-up, a 2800TC will really wake it up, and that 2800 might work pretty good with 3.23s if they are already in there.
So to recap, this is pistons down .010, the .028 gasket, and 59cc heads.

Now I'm not telling you to run the 262 cam. I'm just having fun with math....... You can change the parameters any way you want to run almost any street cam, some combos just look better on paper. Measure,measure,measure. That's the difference between a Fantastic engine, and an also-ran.
>Pressures over 165 usually need 89 to 91 gas under load. But with a TightQ , moparofficial says he runs 185. I can't say one way or another, and to you it doesn't matter, cuz your heads are chosen, and there is no way to get your total chamber volume down low enough to get that much pressure with any performance cam.Well there is but that would take custom pistons.
As for me, I'm liking the 270 with a 2800 and 3.73s

If it helps any, I have run a totally stock low-C teener long block with a 2800,3.55s,the 2.74low A999, headers, and a TQ,in a 3650 chassis, and I had a lot of fun with that. Almost as much as when I ran it with 4.30s and a 4-speed. Actually I think I mighta had more fun with the automatic.

Well AJ , he can slap the heads on the block and correct/grind them to the bore around the valves, that may net him 1+cc a chamber, increasing its total chamber volume, if thats even necessary.

 

[Lee Prim]

Laffin. My next 318 will be aimed at REGULAR and I see post after post here concerned that Premium will NOT be ENOUGH.

 

[Wyrmrider]

What Lee says and the fix is what Mopar Official said not a thicker head gasket
he can get 5cc with a little work and a little less with just a cutter

 

[Lee Prim]

What do you figure is a good number for Static Compression to aim for on a 318 running 87 octane ?

 

[Wyrmrider]

you have to go around in circles a few times
combustion chamber. gears and converter, load, usage, cam, torque cure desired
power below the torque peak desired
for example heavy boat vs light boat, truck, motorhome 360 build vs a little duce coupe- getting the motorhome or truck moving loaded up as hill or getting the boat out of the water up a steep ramp is different
can we use late 302 or the late 360's, Magnum style, Enginequest, aluminum have more tolerance than early heads
so if you already have heads let's start with them
and if you already have weight, gears, trans lets add that in
then what torque are you looking for
cheers
guys- take your shots

 

[AJ/FormS]

What do you figure is a good number for Static Compression to aim for on a 318 running 87 octane ?

Also depends on if you want the most out of it
or just want throw something together to run half-decent
Depends also on where you want the power to be
or maybe you just want to spin the tires
or maybe a lopey idle to be like a poser.
There is a world of a difference in every combo.I suppose there is one 318 engine that could do it all for you, but what is "all"?
Also, you could build an engine to run on 87gas for 85% of the time,but needs best gas at WOT with a 4bbl and headers. In other words; something like a DD on primaries all week, and then put in the good stuff, unlock the secondaries, and have at her all weekend. This was my goal when I built a 185psi 367 many years ago. But to my good luck, it was Ok with 87E10 100% of the time. And furthermore, running 185psi makes for a pretty powerful lil 367. Waaaay more than I had expected.
Had I started with perhaps a 190 psi 323, I'm pretty sure I would have been satisfied...........

 

[Lee Prim]

Also depends on if you want the most out of it
or just want throw something together to run half-decent
Depends also on where you want the power to be
or maybe you just want to spin the tires
or maybe a lopey idle to be like a poser.
There is a world of a difference in every combo.I suppose there is one 318 engine that could do it all for you, but what is "all"?
Also, you could build an engine to run on 87gas for 85% of the time,but needs best gas at WOT with a 4bbl and headers. In other words; something like a DD on primaries all week, and then put in the good stuff, unlock the secondaries, and have at her all weekend. This was my goal when I built a 185psi 367 many years ago. But to my good luck, it was Ok with 87E10 100% of the time. And furthermore, running 185psi makes for a pretty powerful lil 367. Waaaay more than I had expected.
Had I started with perhaps a 190 psi 323, I'm pretty sure I would have been satisfied...........

Long ago I had a 69 Barracuda Notchback. The 318 had a pair of 360 1.88 valved heads to replace the old 318 heads that had cracked exhaust valves. The fix for the wiped cam lobe was a Comp Cams High Energy 260H. Weiand Action Plus with a 625 Carter on top. Converted to Chrysler Electronic ignition. Iron manifolds with 2.25 duals and the old Cherry Bombs. The rest was pretty much stock. This combo was ultra-reliable, ran well on 87 octane, got 19 or better MPG for my daily commute and was MUCH more fun to drive than before these changes. I plan a similar mild 318 for a friend's 67 Barracuda Fastback hoping for similar results but now know that combination has WAY LOW compression. So back to the question. What would be an appropriate compression goal for a guy whose budget dictates that Premium Fuel Only means it will sit in the garage until the Wife gives him the ole "You NEVER drive that old car. Why don't you just SELL it?" speech.

 

[Wyrmrider]

Ok
if we are thinking of a cam in the 256-260 range (would not ever use old comp 260h in 2018 no lift)
I'd build it with 302 heads and 9:1 are you going to build the heads you can think of larger intakes and a multi angle valve job and hand blend
302 are closed chamber wedge with heart shaped chamber and are called swirl heads- all SBM mopar have swirl but evidently these have more
600 AVS carb is about right
I posted a whole list of short cams in the 340 cam thread which we can look at with different LCA's check it out
340 cam specs? see post 27 and 37& 38
the 256 comp is there and several others listed by duration but nothing from Bullet or Engle or Crower but you can get the idea
post 27 reads from shortest on the bottom
Aj what DCR would he have with a IC of 54-56 @.006? about right on the DCL? too much or could he use more with the fuel gotcha?
what pistons to use for -.010 to +.010 deck (for .028 Mr gasket or .48 Fel Pro) gives .038 quench but .028 is also OK
If not rebuilding 302 check out the Engine quest heads any other suggestions? CCs?
If we have to drop to 8.5 then forget the 260 and pick a higher action 256 or would he spring for a custom grind
we can get to the proper DCR either way
any idea what gears are in the cuda?
the 302's end up around 63 cc unless relieved around the valves to say 68 if necessary
guys- give some help on the pistons

 

[nm9stheham]

IMHO.... Putting in 302's and using 526AP stockish flattop pistons puts you around 8.7 for SCR. That gives a 7.3 DCR with 256 duration cam with 112 LSA and 108 ICL; these numbers are with 1008 Felpro head gaskets. That all runs about .5-.7 point higher on SCR and DCR than a stock LA. And using the standard Felpro kit head gaskets 8553PT will only drop SCR/DCR another couple of points so are another budget thing to do. The only real compression gain here is in the heads. Not a HOT smoking engine, but better, and with a good intake and exhaust, and this modest camming, it'll be a sight better than a factory engine. (How is that for technical terminology? LOL)

With these flattop pistons, no re-balance is needed. (That point was never discussed for the KB167's listed in this threads initial build plan.) No re-balance is important for a budget IMHO. But the lift will be limited as these cheap pistons have no eyebrows. so you have to be careful with high lift cams, but something in the range of .475" lift will probably be OK; you still need to check. (Not a show topper anyway IMHO, this can be solved with patience and careful application of a Dremel, or a mill if you have access to one; there is plenty of crown material in these old designs slugs to sink a .100+" eyebrow). These pistons are still .070" or so in the hole so no quench possible, but that is the dilemma with 318's: no cheap near-zero-deck pistons are made for it.

All of your success with any fuel has a lot to do with tuning. The above assumes no real desire to spend hours and days tuning the timing; just put it together, don't work to get everything you can out of the tuning, and gives a bit of SCR/DCR room to be a bit sloppy on timing and not be too fussy on fuel. Low 7's DCR is about all I'd push with regular and be lazy about tuning. AJ has spent TONS of time on tuning and so can get 'blood out of a stone' so to speak in terms of octane versus compression ratios.

 

[rumblefish360]

What do you figure is a good number for Static Compression to aim for on a 318 running 87 octane ?

8.0-1 (or less) for a stock OE cam.
8.5-1 for small aftermarket cams.
9.0-1 for moderate performance cams.

 

[Lee Prim]

Thanks DJones for letting me bust into your thread. I just didn't think it deserved a thread of its own and this seemed like a good place to discuss it. Thanks fellas for responding. IMO compression ratio should be your first target in an engine build and I wasn't sure what would be the proper ratio for what I wanted the engine to do. Compression ratio determines how much cam I can use. Cam selection determines the RPM range of the engine. RPM range helps determine intake type and carb CFM needed. Doesn't this sound like a logical plan for an engine that is still on the drawing board ? I understand that the 302 Swirl Heads are superior in many aspects to the old 587 or 974 heads but I have also found that,even with the compression loss, the 587s add performance compared to the stock 1.78 valved small port 318 heads and the 587 type is cheaper, more readily available and less likely to be damaged. The old 260H worked well in that time place and application but I already knew that we wouldn't be using that one again. I do understand that we should "Aim Low" during cam selection. We are good with that. Not building this engine to impress the kids at the local drive-in only to have it fall on its face out on the boulevard. Been there. Done that. NOT going back. What are the cam companies to avoid due to their total lack of understanding of what an LA engine wants and are there companies that seem to have better engineering when it comes to this sort of build ? Thanks for the help.

 

[Wyrmrider]

actually rpm range could be a close first
HP is torque x rpm so HP gets seductive

 

[AJ/FormS]

actually rpm range could be a close first
HP is torque x rpm so HP gets seductive

Exactly; you gotta look at the whole combo; if the engine is stuck with 2.76s and a stock TC because of budget constraints the powerband is gonna be completely different that with 3.91s and a 2800TC.
Consider 32mph with 2.76s, and downshifted into 2.45 first gear; the rpm will be around 2900... so the engine is gonna need some punch down there to get moving, don't put that into a 4000 pound Chrysler with a 1750TC
Consider 32mph with 3.91s. Downshifting into first, the Rs will rocket to 4150, and KaPow!! you are gone. But if you are not careful, you will be outta revs in a heartbeat.
If you want a tirefryer off the line, listen carefully, the horsepower of the 318 by itself, has nothing to do with it. This is all about TM (Torque Multiplication). The non-stock cam will power-peak somewhere close to 5000. You can't break traction and get there with a 318 and 2.76s and a 1750 TC, it will never happen, and here's why;
Depending on the tires, you are gonna need around 2000 ftpounds to the road to break them loose. Then as the car accelerates, you are gonna need more, to keep them spinning. If you run out too soon, all you will get is a chirp.
Ok so say your teener makes 100 ftpounds at 1750, and you multiply that by the trans and rearend ratios, then correct for tire size and I get;
140x2.45x2.76x24/25.5=891# to the road. Now at zero mph the TC is gonna multiply this some, say times 1.4, and I get 1247# just about 60% of what you need.
So if you want a tire-fryer, you are gonna need to change one or more of these multipliers. The 2.45 low-gear is pretty much fixed. and 3.91s won't get you far enough. Tires don't make a big deal so that leaves the footpounds at the crank; 140 is just too small.
So let's say this is a city car and yur OK with 3.91s; these will get you
140x2.45x3.91x24/26.5=1214 and adding the 1.4TC I get 1700, hey now we're closing the gap. But here is another problem; as soon as the car starts to move, the TC multiplier starts to diminish, ending at perhaps 1.05 about 2 or 3 car lengths out; so with that in mind, your 1700 is gonna drop to ~1275.
So that leaves you with ordering up a hi-stall.
So say you order a 2800 (I love that TC), and say at 2800 your teener makes 220# now.
Ok so
220x2.45x3.91x24/25.5=1985 and The TC pumps that up a lil higher than before, say 1.6 now; and I get 3176, hyup we are frying tires, but can it sustain? Lets say 3 lengths out this has dropped to 2084, just barely sustaining tirespin, but now the rpm is rising so the torque is still increasing for a bit... or is it? IDK, yur engine could be sick. Stock teeners torque-peak pretty early anyway,maybe even 2800, so then no, the torque will not be increasing. but
It doesn't matter that much, because another thing is happening; it takes less power to keep the tires spinning than it does to break them loose. So, this stock-engine combo is now a tire fryer. So if that is all you wanted, say; For the cost of the 3.91s and a 2800TC, yur in business.
Of course the stock cam is gonna power-peak at about 4200 to 4400, but is that a bad thing?
With 3.91s now, and a shift-rpm of say 4500, you will get 35mph in first and 60 in second... so you will be going thru the power peak twice on the way to 60 and then into third. So the cam is pretty much right for 3.91s.
But say you upcam 2 sizes and the power peak moves up 400 rpm and your new shift rpm is 4900. This means in second gear the power peak comes at 60=4540, and you just wasted ~300rpm of pulling power; you need 4.10s now to use it all up. So there is no telling if this now bigger cam is gonna be any quicker to 60 or not. And if it is, will it be worth it.
So what's the answer?
The answer is; more pressure and/or more airflow.
But you have already spent your budget money on the gears and TC.

The thing is, as soon as you open up that 318; it's gonna need gears and a TC anyway, there is no escaping this.
Well there is; To keep the bottom end torque up, you gotta keep the pressure up. And if you really want to keep the bottom end up to run hiway gears, this requires a very careful co-ordination of compression ratio and Intake closing angle, to get full value from the detonation resistance of the gas you have chosen to run.
Or just slam some aluminum heads on it and run 180psi on 87E10; I know a guy who did that on a 367, but there was no budgeting involved there,lol.

 

[fishmens67]

Exactly; you gotta look at the whole combo; if the engine is stuck with 2.76s and a stock TC because of budget restraints the powerband is gonna be completely different that with 3.91s and a 2800TC

lol did you learn this the hard way like the rest of us did when we were green. lol from 3000 rpm she ripped.

 

[sireland67]

Honestly, if you have not spent a dime on the 318, I would order a blueprint 408 short block and be done with it, by the time you rebuild the 318 it will cost the same.
I just got done throwing a dry seized teen together, granted I used stock pistons and a set of J heads, all parts were raided from my parts stash, except the usual, rings, bearings, gaskets and cam.
I did splurge for a new intake and carb.
The results, a super low compression 7.5 static and 6.97 dynamic compression, do I care no, it is just a parts engine, to get a old drag car running, but I am throwing twin turbos on it which will raise the compression up to 11.7 with 10 psi, will it live?
I doubt it but it is just an experiment, too see how far I can push things until they go bang.
But I bet I have 2K in that old scrapper 318, the value for buck is just not there.
Funny thing was I dropped the 318 parts off at the machine shop.
The next day a good friend sold me a good running 340 cheap.
It cost more to tank the block, turn the crank, and have a valve job on the pos teen, than I paid for the 340.
I just built the teen to see how this experiment goes.
My point is, a teen is a nice stock engine, ultra reliable, I have alot of them, but a 340 or 360 make cheaper horsepower.