Looking for 360 advice on a budget.

[340sFastback]

A question for those that said to replace the exhaust rotators with std retainers and locks. I did that on my 360, and they are MUCH further down than the intake retainers. I was going to have different valves installed as I compared them to std retainer valves and the lock grooves were much further down on the valve. Am I safe running them this way? I didn't want to drop a valve. Just something to think about...

Makes me wonder if the locks are not fitting into the retainers correctly? Can you post up some pictures?

 

[rumblefish360]

IMO, IF you do not balance the engine, don't bother with anything else. Close up shop, go home.

No one has suggested Magnum heads because you said "Budget" someplace and a set of Magnum heads is not only the cost of heads, it's also all the gear that goes with it. Hollow push rods, rocker arms.

Take out the calc!

 

[metallidart]

I'll see if I can get some pics today, I have one of the heads off and in my trunk. Comparing them to some old std retainer valves, the lock grooves look much further down. I don't have any real good measuring equipment anymore to measure anything, but I'll get some pics for sure.

 

[metallidart]

 

[Mad Dart]

Looks like you have different retainers on every spring. You sure they all match?? That will affect spring pressures etc. Something is wrong there. Be sure to check it out!!

 

[needsaresto]

IMO, IF you do not balance the engine, don't bother with anything else. Close up shop, go home.

No one has suggested Magnum heads because you said "Budget" someplace and a set of Magnum heads is not only the cost of heads, it's also all the gear that goes with it. Hollow push rods, rocker arms.

Take out the calc!

I have to respectfully disagree on the cost of a magnum swap. The single most expensive component other than the heads is the intake.This can be gotten around by simply drilling the heads to accept LA intakes.Lifter dont count either as any aftermarket lifter comes with an oiling hole Like an amc lifter. Check the part #s and you will see they are the same for sbd and amc. Hollow pushrods dont cost a great deal either,under a $100. You could cheap out and get some used head bolts,but they are only around $50 new. so why bother. The magnums can be bought and installed for under $500 IMHO. Go to the wreckers and get a set thats guaranteed crack free.Probably cost less than $100 for a set with rockers,etc. Hand lap the valves and install new seals,make sure the guides arent too worn.

I have been trying to sell my magnums here but nobody likes paying shipping,lol.

Magnum swaps arent that expensive.I have about $500 into my heads,but they are rebuilt and ready to run with all valve gear.I also bought mine before the eq hit the market. The intro of the eq made used magnums hard to sell!!!

Putting magnums on will get you at least 9:1 with stock pistons.A .450 lift cam gets you around .480 net with the mags 1.6 rocker and about 400 h.p with no porting.

 

[rumblefish360]

I respectfulllly disagree because the expense of purchasing Magnum heads, vlave cover and gaskets, rocker gear and new length pushrods add's up to an expense not needed on a budget build period and will create money spent that could otherwise have been used to upgrade what he allready has.
Also, unless this build gets up in HP, reuse of the head blots is exceptable.

The lifters mostly picked up in Mopar cam and lifter set are AMC lifters anyway, so the expense is moot there.

Hence the word budget, not build on the cheap.

Your $500 expenditure could very easy roll right back into the stock head with new racing valves as well as some basic bowl porting to boot.

All the valve gear would be purchased new anyway sinc changing the cam would require new springs. He can reuse the stock retainer and locks no problem.

A Magnum head swap is very close to "A wash" IMO

The 1.5 vs. 1.6 ratio is something that can be useful or, you could just purchase the right cam to begin with. IF it is not on the shelf, Comp Cams and other manufactures will be happy to custom cut one for you and that is cheap stuff to have done.

 

[rumblefish360]

OH, he also save's on a new intake purchase, even if it is cheap gaskets and a cheap knock off intake.

 

[needsaresto]

OH, he also save's on a new intake purchase, even if it is cheap gaskets and a cheap knock off intake.

He doesnt need a new intake.Just drill the mags for l.a intakes.Then he can use the ultimate cheap cast iron 4 bbl intake.I bet the new head holes could be drilled by himself using aforementioned cast iron intake as a template/guide.

Budget build to me would be refurbishing boneyard heads the shadetree way. New seals,handlap the valves etc,spit clean and polish everything,lol. Magnums can be had cheap right now because of the eq.It's one of the reasons I wont sell mine,the other being shipping.

The other things you mentioned like porting,racing valves etc would not be in a budget build unless he did it himself.

La valve covers will fit on a magnum,so moot point.
He' is likely going to buy new gaskets anyways even on a budget build,so again a moot point.

Magnums can use the g.m 3100 beehive spring which solves the spring expense.

Any used head he buys will come with rocker gear.

He can resell his LA heads to get back some of his money.

Also completely avoids having to buy and install new pistons to raise comp. And no longer needs to fart around with offset grinding and thin gaskets,allthough this could bring his budget motor as high as 10:1 on a stock piston with magnum heads.
and the magnum is a very pump gas friendly head at higher comp ratio's.True part of this is always treating for pre detonation by polishing and smoothing rough spots and sharp edges,but the magnum has built in protection from it's chamber and fast burn.

Anyways,I got sucked into another magnum debate..

 

[moper]

Just run them that way. You won't have an issue.

 

[340sFastback]

Looks like the grooves on the valve stem are lower on the exhaust valve. Some +.050" locks, which are offset to move the retainer up, would help but may not be enough. You need to get members such as moper or ou812 on here to take a look and advise.

 

[rumblefish360]

He doesnt need a new intake.Just drill the mags for l.a intakes.Then he can use the ultimate cheap cast iron 4 bbl intake.I bet the new head holes could be drilled by himself using aforementioned cast iron intake as a template/guide.

True, so long as he don't mind. He he he

Budget build to me would be refurbishing boneyard heads the shadetree way. New seals,handlap the valves etc,spit clean and polish everything,lol. Magnums can be had cheap right now because of the eq.It's one of the reasons I wont sell mine,the other being shipping.

Yea, shipping can be tuff on heavy things. I agree with what you said above. The stock heads could be refurbished the same way.

The other things you mentioned like porting,racing valves etc would not be in a budget build unless he did it himself.

It was a cost compare vs. the purchase of Magnum heads. Not so much budget, i agree.

La valve covers will fit on a magnum,so moot point.
He' is likely going to buy new gaskets anyways even on a budget build,so again a moot point.

I sit corrected. Gaskets are gaskets that are gong to be purchased anyway.

Magnums can use the g.m 3100 beehive spring which solves the spring expense.

I figured in new springs for any new cam. Double moot point ...agreeded on.

Any used head he buys will come with rocker gear.

Not true, but I would hope so.

He can resell his LA heads to get back some of his money.

A '77 360 head worth the price of Magnums? No way, but some recoupe is better than no recoup.

Also completely avoids having to buy and install new pistons to raise comp. And no longer needs to fart around with offset grinding and thin gaskets,allthough this could bring his budget motor as high as 10:1 on a stock piston with magnum heads.

Offset grind what? I didn't do any math on the 360 head vs. Magnum head and what the final ratio would be on the swap. Let me get this straight, a swap between heads would be a jump from a more than 3 points? From what is probably a less than 8-1 ratio to 10 -1?

and the magnum is a very pump gas friendly head at higher comp ratio's.True part of this is always treating for pre detonation by polishing and smoothing rough spots and sharp edges,but the magnum has built in protection from it's chamber and fast burn.

Only if the quench is good. Otherwise, it aint workin.

Anyways,I got sucked into another magnum debate..

No, you try and make you case to the OE poster on your point of view. I'm not going to debate this, I just gave my point of view and I'm done. I just wouldn't go Magnum, you would and that's that! :toothy10:

I'd just rather use the heads I have on a budget build and modifiy them as needed instead of purchaseing new heads. Any head mod to the OE heads can be done rather cheaply with a good result.

You push (Or seemingly) the Magnum head as a better head, which is true if used right in the right arena and combo.

IF a rebuild is not needed and a mild performance engine is sought, the need for excessive head milling is out and a light one maybe worthwhile for sure. Milling the head is cheap and the 1.88-1.60 valves will work just fine for many performance perameters.

He saves on the head purchase, shipping if it applies, and all the gear needed to be purchased up and over the replaceables, which both heads would need on a rebuild.
IMO, the price of a bowl porting would be better, build dependent, which is yet to be revealed by this post.

 

[needsaresto]

Cool Rumble! Lets agree to disagree on the mags then,lol..

I guess the reason that I think that a head should come with rocker gear is that is how I got mine.

Offset grinding the crank is what I meant.Doing this could possibly raise the piston as much as .020 or .030 depending. There are .060 rod bearings available for the 360,so 1/2 of that would be .030. Thin head gasket would help too,like a .024.

I plugged some #s into Desktop Dyno just as a compression calculator.

Lets assume the stock piston is .080 in the hole,which sounds about right.

Also assume an .060 offset grind to the crank. The piston now comes up to .050 in the hole.

.024 head gasket.

Stock 360 bore

Piston .050 down

65 cc magnum chamber

Now the calc gives comp ration as 10.5:1 without taking into account the dished piston. So maybe the true comp is 9.5:1. However change the chamber volume to 63 cc with a light mill of the heads and you get back another .5 of comp which brings it back to over 10:1,something like 10.14:1.

I have a 360 and magnum heads.both are too heavy to ship,lol,so I should do this for it ! Then buy a car that needs the motor..

 

[metallidart]

Thanks moper and everyone else! They are all the same retainers. I thought about some different locks for the exhaust side. I may still look into it. I was just worried about coil bind, they are crane springs, and are good to well over .500, and my cam is only rated at .460 on the exhaust side, not taking into consideration I have stock rockers so I probably won't even see that. I've been meaning to ask about this for a while. Sorry jackel440 if I highjacked your thread, I thought this might be of interest to you too!

 

[jackel440]

Wow you guys keep throwing ideas out there!
Ok now hate me or not,but I am gonna give you some more information.I have a 96 ram with a 360 that threw the rods through the block.I got it in a trade and it came with another 360 to put in it.
So I have a possible set of magnum heads sitting in a truck that I could salvage.
I have not read on what it exactly takes to do the magnum swap or anything.
So here is my question for you guys.I would like to know what avenue I should go down.
1. go with my current plan,new pistons,cam,springs,regrind valves,new gaskets and bearings.have everything balanced then assemble

OR
2. Keep my current short block and rering it with new bearings,cam,and then use magnum heads from engine i have to pull from truck.(?Will this bring my c.r. up enough by just using these heads?)What other parts will I need to use them?I have no problem modifying my intake to bolt on to the other heads.I might try to even get a new aluminum one if I can.

I never thought about the blown magnum engine I have.I was just thinking about what I have on the shelf from the 360.If I could swap heads and get were I want to be without going to the greater exspense of pistons and balancing would be nice.What can I use from the magnums heads if this is the case?Would I only need new lifter and pushrods?
Lay some more info on me as I need to get my plan nailed down.
Thanks guys this is great info.:toothy10:

 

[jackel440]

Thanks moper and everyone else! They are all the same retainers. I thought about some different locks for the exhaust side. I may still look into it. I was just worried about coil bind, they are crane springs, and are good to well over .500, and my cam is only rated at .460 on the exhaust side, not taking into consideration I have stock rockers so I probably won't even see that. I've been meaning to ask about this for a while. Sorry jackel440 if I highjacked your thread, I thought this might be of interest to you too!

Not a problem as I have the same problem to fix.I started another thread on it ,but i haven't checked it yet today.I think we got better info on it here anyways in this thread.

 

[needsaresto]

The magnum is good for roughly .5 of compression,so if you currently have 8:1 it will come up to 8.5:1.Use a thinner set of head gaskets (gotta buy em anyway!) and it will be close to 9:1,maybe a bit higher.

The truck will have everything you need for the swap minus the pushrods and lifters. You will need the complete heads with rocker gear and head bolts as magnum head bolts are different from la head bolts. The lifters will come with whatever cam you choose,so you only need pushrods.Call it $100. Also a magnum intake or drill the heads for la intake.Get new valve springs.Use the GM beehive 3100 spring.It's the cheapest one and the mopar spring costs a lot more. There is also a guy here selling magnum springs.

I would use the mags and balance the engine.

 

[rumblefish360]

The engine allrerady has the thin head gaskets from the factory. There an OE part.

What truck? Did I forget something?

He has a truck? With a Magnum engine in it?

 

[jackel440]

The engine allrerady has the thin head gaskets from the factory. There an OE part.

What truck? Did I forget something?

He has a truck? With a Magnum engine in it?

Rumblefish, :toothy10: I am sorry,Yes I have a magnum in a truck that chucked a rod through the block.It came with another engine to replace it.I didn't ever think about using any of the parts from it,or if they would be worth the hassle of messing with.
SO yes I do have a magnum engine i could pull apart.I don't know if the heads were hurt when it blew up though.
If they are only worth half a point in compression.Is it worth the hassle to use them or should I just use my original heads and get new pistons?
Would I need to get new springs or could I just use the magnum springs that are on them now?
If I use them I would only need new push rods,lifters and maybe valve springs?If that was the case I could actually put this together cheaper than I thought.I could use the money i would spend on pistons to buy an intake.
Man I am going to have to write this all down to get it all straightened out.LOL!:read2:

 

[Robbie2734]

Cool Rumble! Lets agree to disagree on the mags then,lol..

I guess the reason that I think that a head should come with rocker gear is that is how I got mine.

Offset grinding the crank is what I meant.Doing this could possibly raise the piston as much as .020 or .030 depending. There are .060 rod bearings available for the 360,so 1/2 of that would be .030. Thin head gasket would help too,like a .024.

I plugged some #s into Desktop Dyno just as a compression calculator.

Lets assume the stock piston is .080 in the hole,which sounds about right.

Also assume an .060 offset grind to the crank. The piston now comes up to .050 in the hole.

.024 head gasket.

Stock 360 bore

Piston .050 down

65 cc magnum chamber

Now the calc gives comp ration as 10.5:1 without taking into account the dished piston. So maybe the true comp is 9.5:1. However change the chamber volume to 63 cc with a light mill of the heads and you get back another .5 of comp which brings it back to over 10:1,something like 10.14:1.

I have a 360 and magnum heads.both are too heavy to ship,lol,so I should do this for it ! Then buy a car that needs the motor..

That head gasket # is p4120094, It compresses to .024to.028. Thats a Mopar Performance number

 

[vfjohno]

hi guys been reading this thread with interest as it mirrors my build,
with my 69cc heads my measured commpresion worked out in the region of 7.66-1 ordered some 30 over kb107s and should end up around 9.2-1,
just a newbie question but if i get my motor balanced does that mean i can run my original 904 box without having to get a balanced converter or flex plate

 

[rumblefish360]

hi guys been reading this thread with interest as it mirrors my build,
with my 69cc heads my measured commpresion worked out in the region of 7.66-1 ordered some 30 over kb107s and should end up around 9.2-1,
just a newbie question but if i get my motor balanced does that mean i can run my original 904 box without having to get a balanced converter or flex plate

This is thread hi-jacking. This is a question worth it's own thread.

Your KB-107's should get you 9.8-1 if there zero deck height.
When you get the assembley balanced it will be your choice of ether internal or external.
A 360 is factory balanced externally and if done so, you can reuse the 360 converter and what ever tranny with the proper OE flex plate.

If you have it internally balanced, you can run a neutral balance converter with the proper OE of otherwise flexplate. And with every trans you want.

Your post is questionable since you give no real details.

Your OE box is a 904 that was connected to what? You changed engines?
Start a thread.

 

[rumblefish360]

Cool Rumble! Lets agree to disagree on the mags then,lol..

I guess the reason that I think that a head should come with rocker gear is that is how I got mine.

Offset grinding the crank is what I meant.Doing this could possibly raise the piston as much as .020 or .030 depending. There are .060 rod bearings available for the 360,so 1/2 of that would be .030. Thin head gasket would help too,like a .024.

I plugged some #s into Desktop Dyno just as a compression calculator.

Lets assume the stock piston is .080 in the hole,which sounds about right.

Also assume an .060 offset grind to the crank. The piston now comes up to .050 in the hole.

.024 head gasket.

Stock 360 bore

Piston .050 down

65 cc magnum chamber

Now the calc gives comp ration as 10.5:1 without taking into account the dished piston. So maybe the true comp is 9.5:1. However change the chamber volume to 63 cc with a light mill of the heads and you get back another .5 of comp which brings it back to over 10:1,something like 10.14:1.

I have a 360 and magnum heads.both are too heavy to ship,lol,so I should do this for it ! Then buy a car that needs the motor..

IMO, that is alot of work worth nothing since offset grind the crank and all the work with it is just alot of work and money spent for what? A few cubes and no valve reliefs?

New slugs (KB-107) are 200 bucks and rings are cheap, he balance job is 300 on top and you end up with 9.8-1 if zero deck height is achieved. (Iron head)

 

[360moparjunkie]

hi guys been reading this thread with interest as it mirrors my build,
with my 69cc heads my measured commpresion worked out in the region of 7.66-1 ordered some 30 over kb107s and should end up around 9.2-1,
just a newbie question but if i get my motor balanced does that mean i can run my original 904 box without having to get a balanced converter or flex plate

Welcome, this site has been priceless to me and my build thus far. I'm new as well.

I recently had my 360 assy balanced.
They wanted to know my intended tranny....I chose 904.
I took a new b&m flex plate to my balance shop with the norm (new pistons, rods, crank, new harmonic balancer...think thats it. (fyi, I could have bought an sfi rated balancer for just 30.00 more. Live and learn.)

After balance is complete I was told by my shop that since I now have a balanced assembly I am to use a neutral balanced convertor when the time comes.

As usual, other more experienced builders on the site can probably help you even more....just my 2 cents.

 

[needsaresto]

Offset grinding doesnt cost anything extra,at least not with my machinist. He said set up time is the same so why not?

The dish is your valve relief,lol!! Seriously,this is a bucks down approach on how to get 10:1 with a stock piston.

I think the dish is actually a help in this case.Gives more room for lift,lol!