Need some advice on some cylinder head gaskets

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850 is certainly doable but you’re going to run up against the strength limits of the block. I recommend not trying to find that limit. Don’t think of giving up power by limiting the compression ratio. Think of it as a safety margin to be able to run boost more efficiently. How bout we ask a couple of questions. What are your goals for this car? Race? Street? Trying to hit an ET target? Have you ever driven a car with 600-700-800hp? These are serious questions.
It is a street car, and I would like to occasionally visit to the track.
NA, I never was satisfied on how quick it was. I was happy with the torque though. I think the fastest car I’ve driven was about 650-700hp range.
Oh, I’d like to get low 10’s high 9’s which I know isn’t too realistic, but I can dream lol
 
For long term strength concerns of the block, I would consider a minimum of having ring dowels installed in the caps and block along with cap straps or a Hughes engine girdle (I would install ring dowels either way). My machine shop operator made a pro charged 318 based 391 live under a lot of boost with water meth injection (600+RWHP) and cap straps with ring dowels. It regularly went 9.80s in a Duster. I really don’t know where you’re expecting to lose power other than maybe barely off idle and low rpm cruise. The only way it won’t make more power when it’s coming into boost is if it breaks.
 
I think your ET goals are more realistic than your hp goals. Regardless, you’re casually asking about pushing your na build about as far as anyone has pushed a factory 360 block even purpose built for boost. 500hp naturally aspirated says your cam will likely be a poor performer in a turbo application; those small(looking) turbines will only worsen the cam mismatch. We need more info:
Cam, ring gap, turbo specifics, intercooler flow, and what computer are you running this all with? I’ve heard the Edelbrock software is lacking in flexibility which would be another hurdle.

If you want to do this right, and only one time, you need to pull the engine and swap pistons, cam, and possibly turbos. If you don’t mind the elevated chance of failure then you can toss some cometic’s on to trial and error this thing to low 10’s just depends on what kind of person you are and how much time you have on your hands.
 
For long term strength concerns of the block, I would consider a minimum of having ring dowels installed in the caps and block along with cap straps or a Hughes engine girdle (I would install ring dowels either way). My machine shop operator made a pro charged 318 based 391 live under a lot of boost with water meth injection (600+RWHP) and cap straps with ring dowels. It regularly went 9.80s in a Duster. I really don’t know where you’re expecting to lose power other than maybe barely off idle and low rpm cruise. The only way it won’t make more power when it’s coming into boost is if it breaks.
Ya, I think changing the pistons is the way to go. If it means anything, I do have a 4-bolt main spaded
 
I think your ET goals are more realistic than your hp goals. Regardless, you’re casually asking about pushing your na build about as far as anyone has pushed a factory 360 block even purpose built for boost. 500hp naturally aspirated says your cam will likely be a poor performer in a turbo application; those small(looking) turbines will only worsen the cam mismatch. We need more info:
Cam, ring gap, turbo specifics, intercooler flow, and what computer are you running this all with? I’ve heard the Edelbrock software is lacking in flexibility which would be another hurdle.

If you want to do this right, and only one time, you need to pull the engine and swap pistons, cam, and possibly turbos. If you don’t mind the elevated chance of failure then you can toss some cometic’s on to trial and error this thing to low 10’s just depends on what kind of person you are and how much time you have on your hands.
So let’s say hypothetically, if my piston surpasses the deck by .010, I would need to put a head gasket thickness of .050 to match the .040 quench? And if that were the case, I’d still be closer to 10:5-1 cr than to 10:1 cr
 
What kind of 4 bolt splayed cap block do you have? The more I hear, the more it looks like you need to start fresh. One concern here is piston ring material, too. I don’t know what kind of rings you say you have, but I would be looking at some steel top rings here. Anyone else ever have the moly flake off their rings?
 
What kind of 4 bolt splayed cap block do you have? The more I hear, the more it looks like you need to start fresh. One concern here is piston ring material, too. I don’t know what kind of rings you say you have, but I would be looking at some steel top rings here. Anyone else ever have the moly flake off their rings?
It’s whatever the rings are in the kit. I think it’s ductile iron
 
I keep thinking about those turbos. Since it looks like you’re still fabricating the hot side I’d suggest, above everything else in this thread, that you stop and verify the specs on those before you proceed with the downpipes and waste a lot of time. To me they look like uncontrollable boost, and too much back pressure to make power past 4K rpm on a 400” engine.

You could find suitable replacements for under $200 each…not including wastegates.
 
I keep thinking about those turbos. Since it looks like you’re still fabricating the hot side I’d suggest, above everything else in this thread, that you stop and verify the specs on those before you proceed with the downpipes and waste a lot of time. To me they look like uncontrollable boost, and too much back pressure to make power past 4K rpm on a 400” engine.

You could find suitable replacements for under $200 each…not including wastegates.
These are the ones that came with the kit TURBO + OIL DRAIN + FEED + INTERNAL WASTEGATE TURBOCHARGER INSTALL KIT T3/T4 SS | eBay
 
I keep thinking about those turbos. Since it looks like you’re still fabricating the hot side I’d suggest, above everything else in this thread, that you stop and verify the specs on those before you proceed with the downpipes and waste a lot of time. To me they look like uncontrollable boost, and too much back pressure to make power past 4K rpm on a 400” engine.

You could find suitable replacements for under $200 each…not including wastegates.
I also bought the ic982 pistons, and plan on buying cometic.040 thickness gaskets
 

That listing doesn’t show turbine wheel specs, but I’m still 90% sure they are wrong for your engine. You could email the seller and ask for compressor and turbine wheel specs, or pull one of your turbos and measure yourself.

This will be useful for you:
Turbo change

Those pistons were a great purchase. I wish they had dish options like those for stock stroke 360’s
 
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The SCE's I had drooled coolant and I didn't want to mess with them after that. Also used a copper gasket in a 4 cylinder 10:1 car and they worked awesome.
The SCE's look cool hanging on the wall so I give them that.
 
The SCE's I had drooled coolant and I didn't want to mess with them after that. Also used a copper gasket in a 4 cylinder 10:1 car and they worked awesome.
The SCE's look cool hanging on the wall so I give them that.
Yea, I bought the Cometic MLS’s. Just have to wait now for parts. Should have me down to 8.8:1 when it’s all said and done.
 
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