What type of head gasket shouild I use?

[crazypurgatory]

I have what I though was a 383 for my 71 Camaro but it's not a 30' over bore its a "60" over bore and I have a weiand supercharger that's going on it.
The piston's are L2256 0.60 can't seam to fine much info on the pistons I believe they are forged?
What gasket should I use I was thinking of a fel pro permatorque mls head gasket?
But I have know idea what size and thickness to get.
I'm going to pull the other head off tonight and see if I can see the mod# on the head gasket.
Let me know If you can help me.
Thanks,

 

[Dogwater]

I'm guessing you know that the compression needs to be low to run a blower, not sure how low but around 8.5 or 8.9. You need to measure how deep in the hole the pistons are, need to know how large your cylinder head chambers are an add in that it is 60 over also. You'll need to plug all that info into a compression calculator. Then you can figure out how thick of a head gasket you'll need. I'm just saying this because your pistons are unknown.

 

[hhott71]

2256 is a forged 350 piston
Do you have 5.56" 400 rods?
If not, I'd drop a ruler down in the cylinder.
3 1/2' IS A 357, 3 3/4" IS A 388

You want a 0.040" quench. On an undecked block that means the Felpro 1094 which is 0.015" thick.

Losing compression with a thick gasket on a wedge head engine will result in ping and knock.

You will be at 10.5 with the 357, 11.1 with the 388 using 54cc chambers
You will be at 9.2 with the 357, 9.8 with the 388 using 76cc chambers.

A blower won't work well with that much compression unless you fuel it with e85 or Methanol.

You will need reverse dome pistons or dished pistons.
Don't know of any dished forgings.

 

[CorkyE]

Those look like my old TRW forged units, no problem there. Which Weiand supercharger you going to use? In a forced induction engine, getting the static compression ratio is more important than quench area. E85 is always a good option when super/turbo charging.

 

[crazypurgatory]

Ok here is my update on what I know about my engine.
not sure on the stroke when I go the car he told me it was a 383. with that being said it does have the 400 balancer on it so I would think it has the 400 crank.
It has World Products' SPORTSMAN II Iron Heads.
http://www.theengineshop.com/produc...rolet-iron-heads/sportsman-ii-iron-heads.html
The head gasket that came off it is a Fel-Pro 103.
http://www.summitracing.com/parts/FEL-1003
Pistons are L2256 0.60.
http://www.summitracing.com/parts/slp-l2256f60/overview/
I have a Weiand 144 Supercharger I was told it should fit under my 4 inch cowl induction hood.
https://www.holley.com/products/superchargers/supercharger/parts/7750-1
I don't know my cc size of my heads I'm going to call up World Products' tomorrow and try to find out what the cc of the heads are.
I'm also going to see if I can give them all the info I have and see if they can recommend a head gasket for the engine.
hhott71 thanks for the info any more help you can give me I would appreciate it.
CorkyE E85 is available close to me but I don't think it's widely available in south Florida I never thought to use that on this engine.

Just so everybody knows what I'm doing I'm putting head studs on the engine because of the supercharger.
I'm also going to pull the cam so I can see what it is.
The engine ran great no problems at all he told me it was rebuilt and had very low miles on it.
It's very very clean pistons are too I was able to clean the tops to see the part# with ease with some brake clean.
In any case I should know more about the heads tomorrow if I got the right numbers off the heads.

 

[hhott71]

400 balancer and I'll assume flexplate too would mean a 400 crank and 400 rods with 350 pistons. 3.75 ÷ 2 = 1.875 +5.5625 + 1.5625 (350/400 pin height) = 9.00" Block is 9.025" tall leaving 0.025" deck height.

If the heads are 64cc you are at with the proper quench you are at 11.12:1 compression
With the 72cc chamber heads you are at 10.18:1 compression

Both are far too high of compression to use a supercharger on.

Even with the thickest head gasket and 72cc heads it is over 9.38:1 compression, STILL too high and you lose the quench.
Custom made FORGED 18cc reverse dome pistons would possibly do it for your compression reduction. Expect to spend a grand for them.

 

[CorkyE]

And to make matters worse, the block has likely been decked somewhere along the line, bringing compression ratio up a bit more. If you're dead set on going the blower route, a set of pistons is in the cards.

You could just throw a bottle of juice in the trunk.

 

[scot1074]

Way to much compression. DO NOT put that little supercharger on that engine. Darn I had a 350 and put the weiand 177 on it but I don't remember what slugs I used. They were dished though. I ran that SC with brodix track 1's. Thing was a monster. The only thing was, I had 1 block bored and honed 30 over, it was from an 84-86 chevy truck. It was a 350 4bolt. I put in 2 different crane solid flat tappet cams and it seems that I was twisting the block. The 3 interior cam bearings were wiped out, along with a lobe or two. At the time I just chalked it up to the cam lobes wiped out first and metal at the cam bearings. Thing is, no other bearings were messed up. So I thought that maybe it was a weak block. Then I had a 350 4 bolt from 68 bored and honed. This time I went roller. This was about 10 or so years ago when crane had a bad bunch of cores I believe. Anyways through all my babble I'm just saying those superchargers work real nice. I have no doubt in my mind that you will grenade that thing the second time you floor it to smoke the tires. If it gets that far. Sorry for the bad news bud but I just can't see not saying anything then a few months from now reading that you put up another post with the title reading $x,xxx amount of money down the drain! Where did I go wrong? Good luck Remember 8-8.5 to 1 max compression with a SC.

 

[crazypurgatory]

Well thanks for all the info.
I called world products about the heads and they told me they can't tell me the cc of the heads so I will try to cc them today.
I have to know what I have.
Is there a way that I can see if the block has been decked?
I ran a strata edge over the block and it's supper flat.
There was a magazine that took a high compression 383 and put the 177 on it and they said it ran great and did not blow up.
I guess I will have to find the article and post it.
I understand what everybody is saying but this article says it can be done.
And I believe now that I'm thinking about it that holly did a 383 with there super charge on it too.
In any case I will post up what I fine out late today about the cc of the heads.
When I fine a syringe that has cc.

 

[hhott71]

I got a 50cc syringe from a Vet, I guess a horse got a shot You may be able to find one there.

The deck should be straight from the factory. If the deck has swirl like cutter marks it has been decked. If the tool marks are in a straight line from end to end the deck is stock.

You can bolt a blower on a 11:1 engine and run 2 lbs of boost along with race gas. It won't boost power any, but it can be done. 1 750 Holley DP wnd the RPM airgap intake will make your best induction system.