Help me please tryin to beef up 318

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I would also advise against the 360 heads on a 318. Not only will they lower the compression but they will also cut down the flow because of valve shrouding which means you would also need to notch the cylinder walls in addition to milling the heads and intake. I would suggest the 302 casting 318 heads that were made in the very late 80s. They have a closed chamber which would raise the compression and if you could get somebody to port and polish them they are some of the best flowing of all the LA heads.

Honestly though, if you really want to increase power there is no substitute for cubic inches...like a 360 magnum perhaps. Or you could use NOS. That would blow the stangs doors off. Probably blow your engine up too but it would be fun for a short period of time.
 
4bbl, cam and exhaust can get you pretty far especially with gears which will smoke that 5.0L. 318 heads are pretty much a cork if you want over 300 hp. Magnum heads would be the best bet if trying for more hp. Me and my cousin have done a few of the 360 head swap and they've always seemed to work even though on paper they shouldn't and I don't believe in the ports being to large, 318 heads (originally 273) are to small more than 340 heads being to big. But with all the magnum choices there the best bet. If you need to go next level in 318 performance.
 
I have some 360 heads on my 318 and the engine runs strong. They were from a mid 80's 360. I used the magnum pistons [Melling brand] which gave me some more compression and also utilized the flat face chevy valves by installing chevy guides. The flat face valves raise the compression some more. I also shaved the block but only like .015. stock head gasket and I ended up at 8.9 compression. I only skimmed the head to straighten the gasket surface with a .005 cut with a grind-stone. I also used the 360 intake and the original mopar Q-jet carb which came on the 360. Used a melling camshaft that is somewhat mild {RV spec} and stock exhaust manifolds. It's in my truck. Used some leftover 5.0 Ford valveprings that the machinist gave me for pennies on the dollar. The intake valve size was the 1.92 size so with the .030 over pistons, the valve shrouding is not much worse than stock. Engine is extremely strong for a mild 'teener and will smoke the 235/75-15 tire in 2nd gear {granny tranny}. Not bad considering the heft of the 4x4 power wagon with a steel flatbed. {that I built}. I think this would be a good combo in a light weight A-body. Yeah its not a 340 but for some stop light action, I think it would suffice for a young person just starting out in the hobby. Just my opinion for a cheap set up 'teener. I'll look for the build sheet for more of the details but most of the parts came out of the melling catalog and were very reasonable priced.
 
My 318 was decent, nearly stock fox body fast, with 4 barrel, MP dist. and control box, 2.94 gears and a 2200ish stall. The 5.0 only has ~225 HP. But that was quarter mile, and my dart was SLOW off the line.... The addition of headers did almost nothing for me with stock heads and cam.

I later changed to a big cam, "302" heads and thin head gaskets. Man it ran good, should have easily taken out a stock to mild fox body, but not 300 HP... I never raced it though, as I had a crankshaft issue. Now I am building with some compression.

I wouldn't recommend the 360 heads without good pistons, but since your budget is tight you could get away with them with a midrange cam, thin head gaskets, and a lot of gear, like 3.73 or more.

Also since your 318 was rebuilt we have no idea what pistons you have or how far down in the block they are. So it is more like guessing
 
Advance timing curve, good intake, good headers' / dual exhaust, a 600 cfm 4 barrel carb, is the standard start, then cam, then stall converter, you could bypass airconditioning if you have it... and swap to manual steering.

But eventually you will want to deal with your heads, nothing makes power like better breathing heads, except dipping into the bottom end (bore, pistons, etc)


Just remember, there will always be someone faster... unless you are in a small pond and/ or have plenty of cash.

If you can do a mod or two, so can he.

Enjoy the ride. And not just the beginning.
 
If anything, Magnum pistons would give less compression. But, the compression difference in Magnum engines does not come from the piston. It comes from the Magnum heads and the shorter Magnum deck height.

Stock LA 318 pistons have a 1.741 compression height. The Magnum does offer a 1.745 compression height, but that's only a .005" difference.




I have some 360 heads on my 318 and the engine runs strong. They were from a mid 80's 360. I used the magnum pistons [Melling brand] which gave me some more compression and also utilized the flat face chevy valves by installing chevy guides. The flat face valves raise the compression some more. I also shaved the block but only like .015. stock head gasket and I ended up at 8.9 compression. I only skimmed the head to straighten the gasket surface with a .005 cut with a grind-stone. I also used the 360 intake and the original mopar Q-jet carb which came on the 360. Used a melling camshaft that is somewhat mild {RV spec} and stock exhaust manifolds. It's in my truck. Used some leftover 5.0 Ford valveprings that the machinist gave me for pennies on the dollar. The intake valve size was the 1.92 size so with the .030 over pistons, the valve shrouding is not much worse than stock. Engine is extremely strong for a mild 'teener and will smoke the 235/75-15 tire in 2nd gear {granny tranny}. Not bad considering the heft of the 4x4 power wagon with a steel flatbed. {that I built}. I think this would be a good combo in a light weight A-body. Yeah its not a 340 but for some stop light action, I think it would suffice for a young person just starting out in the hobby. Just my opinion for a cheap set up 'teener. I'll look for the build sheet for more of the details but most of the parts came out of the melling catalog and were very reasonable priced.
 
Just remember, there will always be someone faster... unless you are in a small pond and/ or have plenty of cash.

If you can do a mod or two, so can he.

Enjoy the ride. And not just the beginning.

I chuckled when I read: "I want to smoke any car that wants to line up with me on the street...'' but didn't take it literally...
 
I was right where you are once. I used 360 heads on the 318 with good results. I cut them .045 and did not do anything with the intake or pushrods, worked fine. I had a cast intake/TQ carb from a maxi van, a used 340 cam for free, and with a stock 727 and stock converter, 3.21 gears it went 14.40's at 96 mph. My stall was only 1800 rpm's. If I would have had a 904/factory converter (usually about 2000 stall), I would have been real close to breaking into the 13's.
 
I just want to have this dart as a lil street rod my grandpa has a 69 dart with a 426 crammed in it and a 66 nova with a ls3 this was given to me to be a toy/project I'm just looking to be the "cool" guy in high school right now I always have the best looking car in the lot now I'm shooting for the fastest so overall it sounds like most people are in favor of getting rid of the 360 heads so that leaves me with a preformance intake and a 650 Holley so what should I do in replacing the heads
Could I get a list of parts that I should look into please
 
So it might be in his budget(and worth it??) to have them cut down a bit, and maybe a valve job before he puts them on.

Just remember you will be a little bit lacking in low end so you will have to make up for that with gears, so find out what you have. And give it as much timing as it will take.

And when you are ready to order your cam, do some research on here then present your choices and see if everyone shoots them down or not.
 
I just want to have this dart as a lil street rod my grandpa has a 69 dart with a 426 crammed in it and a 66 nova with a ls3 this was given to me to be a toy/project I'm just looking to be the "cool" guy in high school right now I always have the best looking car in the lot now I'm shooting for the fastest so overall it sounds like most people are in favor of getting rid of the 360 heads so that leaves me with a preformance intake and a 650 Holley so what should I do in replacing the heads
Could I get a list of parts that I should look into please

EQ's or any of the aftermarket magnum heads all come in closed chamber (more CR) plus bigger ports like the 360 heads. Win win.
 
Damn. Just DAMN. Good luck with it man.
 
Hey please feel free to say anything you'd like I'm new to this type of stuff okay so this is what I've got going I've got a 1973 dart swinger with a 318 in it the motor was rebuilt 3-5 years ago I want to beef it up so I've bought a Holley 650cfm 4bbl carb an eldelbrock performance intake and a set of 1973-1974 360 heads and I'm in the process of buying new headers and a cam so my question is what do I need to do to the heads? I've heard they need to be milled but how much what other work needs to be done before I do that please leave me any information you have this car is my little hot rod my great grandpa gave me before he passed and I'm a senior in high school now and I want all the motor work finished by prom this in April 2016

Geez,the kid has something to work with, he gets arguments.. Holley carb & the Performer intake is workable,big time. Are you doing a full assemble,or just a top end( carb ,heads, intake ,& cam combo)? Unless you have a free head porter/machinist on campus,use stock 318 heads..Headers,obviously.. Depending on you budget ,& wrenching skills: If new to the game, a Summit racing cam lifter set:K6901 kit, (basically a 340 cam set,it works really well,on a budget. Not high lift,I really recommend new stock 340 springs,if possible..) You wanna beat someone with a mild 5.0,on a budget? Work the chassis! Post a few threads about that,that's where your real low buck wins come from.. It involves shock valving, tire clearance, pinion angle, & a limited slip would be nice, not necessarily. ( Do your research, ask questions here, & ask interactivley.. Lots of E.T in chassis ,on a Mopar, lots of money to be spent on a Fox body setup to be quick. Been there...You wanna win, you need to do research, & get dirty.. Ask for help,you might be surprised.
 
$1200....360 swap with some cheap bolt on parts.

318's can make great power, but not for $1200.
 
I just want to have this dart as a lil street rod my grandpa has a 69 dart with a 426 crammed in it and a 66 nova with a ls3 this was given to me to be a toy/project I'm just looking to be the "cool" guy in high school right now I always have the best looking car in the lot now I'm shooting for the fastest so overall it sounds like most people are in favor of getting rid of the 360 heads so that leaves me with a preformance intake and a 650 Holley so what should I do in replacing the heads
Could I get a list of parts that I should look into please


You could have the 360 valves installed into the 318 heads. I have a set of 67 318 heads that I had my head guy install 1.88" intakes and 1.60 exhaust valves from a set of 360 heads that I had converted to 2.02" and 1.60" stainless valves and then ported them. (I'm recycling valves to save the planet...)
 
The 360 heads will lower your compression down into the 7s because those heads have bigger chambers than the 318 heads.

You cannot make up 2 compression points with a .040" cut. Ain't happenin. About .0067" equals 1cc on a 340/360 head. About 6ccs equals one compression point. So that means you will have about an .080" cut on the heads to equal two compression points. So all that work on the 360 heads is really useless, IMO, because a machine shop will charge a pretty penny for a cut that big, since most shops will have to make multiple cuts.

Don't forget then you will also need to cut the intake a similar massive amount to match the heads, so even more money there.

IMO the best thing to do is stick with the 318 heads. Do a mild build on the engine. Use the thin head gaskets from Mr Gasket. I think they are like .025".

Pick out a cam on a wide center line around 112 to 114 and no more than 220 @ .050 duration and you should have a really peppy little 318.

Or, you can spend a pile of cash milling metal off.

Stock 318 head chambers are 68 cc while .040 milled 360 head chambers are 65 cc. I fail to see where the drop in compression occurs. The 360 intake ports flow 190 to 200 cfm up from about 170 cfm for a 318. I would not mill any more than .040 and you mill the intake side of the head, not the intake manifold.

You remove .0048 from the head surface to subtract 1 cc from the chamber on 340 / 360 heads. Chrysler Racing manual and from my experience is dead on.

If you are not changing heads why bother changing head gaskets? Just use the Performer intake, 4 barrel carb, cam, lifters, valve springs, and tune that rascal in. Add Dual exhaust and be done. Maybe a 3.21 or 3.55 gears. One thing at a time so he does not get overwhelmed.
 
Stock 318 head chambers are 68 cc while .040 milled 360 head chambers are 65 cc. I fail to see where the drop in compression occurs.

I've had stock 360 heads at 72 cc's...

I have a set of 67 318 heads that are supposed to be 57 cc measuring at 63 cc.... :banghead:


My brother once gave me a 318 short block with 10.5 forged pistons in it. I used the top half of my 68 318 to complete it and throw it in my car for under $400 out of pocket. It would overheat when the temp got above 80° due to the high compression...

I installed a set of 77 360 heads and never had another problem with it. There was enough of a compression drop to get it to run on cheap pump gas, it didn't need premium...

There was enough of a compression drop....
 
old school - first time hotrodder 101 - an aftermarket (Edelbrock is common) intake, a 4 barrel carb. (someone said 600cfm - sounds right) with a GOOD air filter, headers and dual exhaust, aluminum wheels all around with as big a tire as you can fit on the back (which sadly isn't much with a stock suspension), lower the rear of car if you can AND loosen up the leaf springs - I believe this is done by removing the forward facing leaf spring clamps... in case you are considering it - do not use traction bars. And remember - lighter goes faster - maybe loose the front bumper and brackets and go hoodless... ?? the 360 heads are a questionable "upgrade" - My 2c... :twisted: Keep tweakin' it 'til you get him!!
 
The OP has only $800-1000 to work with and realistically 5 months maximum. He needs suggestions that will help him in this budget and time frame. This is limiting and will put him on a path that is likely to be suboptimal if he were starting from scratch and going for max HP, but it is what it is. He has his whole life to do it again and better, and ANY build will be good learning!
- Other heads are out unless it is the 302's but he has the 360 heads already bought
- Magnum conversion is very probably out due to the budget limits
- New pistons are out due to budget and time, so getting to a higher CR is only going to happen if he moves over to the 302 heads or shaves the 360 heads
- Not likely going to be able to do a new torque converter on this budget to support other mods. So high revving, large duration cams are out.
- He MIGHT be able to change rear gears IF he has the support from his grandpa or someone else to get it done cheaply; he does not have the budget to have it professionally done. better valve springs go hand in hand with a higher rear gear, so that is a cost of the higher rear gear; the 2 together can buy a lot.
- SureGrip is probably out due to budget unless he just gets lucky shopping around. With out this, going too high on the rear gear is a mistake as it will just be spinning all over the place. But it WILL do great burnouts on one side! Keep the rear gear in the moderate range.
- Being the 'fastest in the parking lot' depends....not necessarily going to happen on this budget. And 300 HP is likely out of the budget here. So just be aware of that, OP.

OP do you have someone to help you do a rear gear change? That can buy you a lot for the $$ IF it can be done by you and your grandpa in his shop. (Which I am assuming he has.) Do you know the rear gear ratio in your car now?

OP, do you have any access to other heads like the 302 heads? Do you have any decent junkyards around? (And we are not talking about Ford or Chevy 302 heads but small block Mopar 302 heads!)

I can see a coupla paths that I would do here:
1) 302 heads if he can find some cheap and sell off the 360 heads. Get a high quality multi-angle valve job with a deep angle cut right under the seats to open them up there. If he is skilled enough and so inclined, he can do some basic porting with some help. This will be a better CR combo and keep the rear gear if it is not too low, and a moderate cam. This makes it a lower RPM, better torque engine, and should work OK with the stock TC. Use a moderate cam like the Voodoo 262 duration with new dual valve springs. Throw in a rear gear in the 3.55 range if that is in the budget and scope of abilities.
2) Use the 360 heads with the same good valve work, and mill them maybe .050-.060" with a matching cut on the intake side. Will help the CR and get the cc's down in the mid 60's range. Make up for the larger ports with 256 duration, gobs 'o torque type of cam. (Like the Crower Baja Beast.) Keep the stock TC. The larger intake and headers will do a lot more than people think to make up for the lower duration cam on the high RPM's. But he will need better valve springs for any higher RPM's. Do the rear gear if in the budget and scope.

OP, with either option above, the tuning for ignition timing is critical. It is tedious but is critical and very important to do.

OP, since you will be using a flat tappet cam for budget reasons, it is 100% important for you to read up on using the proper break-in oils and procedures and the oils you use for regular running. The proper levels of Zinc additives need to be there.

Best of luck with this!
 
ah yes, as nm9stheham basically said at the end there - heat it up too, better plugs, better wires and a better coil at LEAST. ..get the tuning/timing right.
 
I've had stock 360 heads at 72 cc's...

I have a set of 67 318 heads that are supposed to be 57 cc measuring at 63 cc.... :banghead:


My brother once gave me a 318 short block with 10.5 forged pistons in it. I used the top half of my 68 318 to complete it and throw it in my car for under $400 out of pocket. It would overheat when the temp got above 80° due to the high compression...

I installed a set of 77 360 heads and never had another problem with it. There was enough of a compression drop to get it to run on cheap pump gas, it didn't need premium...

There was enough of a compression drop....

Your numbers are good. I was equalizing the chambers within .2 cc's of NHRA minimum volume. That is where everyone gets their numbers (NHRA minimum volume) from, but virgin castings fall in what you measured. So milling .040 number gets the largest chamber to NHRA minimum volume, and I'd polish the smaller chambers to match the largest. That .040 cut also works for 318 and 273 chambers to get down to NHRA minimum volume.
 
Here's a link to an article about the different types of heads that could be used.

http://www.hotrod.com/how-to/engine/mopp-0607-mopar-cylinder-head/

My suggestions for a 318 would be either the 302 castings or some of the newer magnum heads. The 302s can be found pretty easily in junkyards or on ebay and are relatively cheap because not many people use them in rebuilds. They were made from 1988 to 1991 I believe. These heads can be used in stock form and will give an increase in compression but to really wake them up they need to be ported, especially on the intake side.

The magnum heads actually flow much better than the 302s and will also raise the compression but there are a couple of problems that would have to be dealt with. One is that the magnums use different rocker arms, lifters, pushrods and intake manifold so all of those items would have to be changed as well. The other problem is that the stock magnum heads had a tendency to crack so finding a good pair would require a bit of searching.

Of course since you already have the 360 heads you could always have those milled. That would be my third choice after the 302s or magnums. Why don't you look around and see what you can find and how much it would cost before you make your final decision on the heads. I know when dealing with a limited budget you sometimes have to use what you have rather than what you would like to have.

Another suggestion I would make to improve performance is to remove as much weight from the car as possible. Every 100 pounds you remove is equal to about a tenth of a second in the quarter mile and it doesn't cost anything to take unnecessary stuff off the car.
 
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