Using 3.4 iron head gaskets to raise compression?

[TazMan]

I thought I read in a post somewhere that you can raise your compression a little bit by using a head gasket from an iron head 3.4 on an aluminum head 3.4. Am I remembering this right and if so will it work on a 3.1 with 3400 heads?

[bszopi]

9.37 vs 8.92 is what I calculated using the site CR Calc.

[TazMan]

Thanks alot. So then I assume I can also use them on my 3.1. I'm really not sure what the difference in those numbers means in terms of power gains but I assume higher is better as long as there's no blower. Will the height difference cause any problems where the LIM meets the heads? Also, what cars had these iron head motors

[SappySE107]

I know the iron head 3.4 gasket is .040 and you can get a performance version from felpro. I am not sure what fitment issue you may have as I haven't used them. There may be a 3.1 version. 93-95 camaro is the 3.4 iron head, and I don't know the specific years for the camaro vs 2.8 or 3.1.

[ForcedFirebird]

2.8 until 1989, 3.1 90-92, 3.4 93-95

[TazMan]

I am not sure what fitment issue you may have as I haven't used them. There may be a 3.1 version.

Is there anybody out there that has tried this and can confirm whether it would work wih the 3400 Aluminum Heads on a 3.1?

[Superdave]

should work fine, all the coolant passages are the same... If heads will interchange so will the gaskets. Many people have done that w/o problems. Just don't do it to a 3400 or you may run into piston VS head problems...


Why use 3.4 gaskets on a 3.1? just use the 3.1 Camaro gaskets, they're thinner as well and actually fit the bore better.


ROL makes great quality gaskets, and they're good priced as well.. I'm running their .045" compressed 3.4 gasket on my 3500. Autozone can get them...

[TazMan]

Why use 3.4 gaskets on a 3.1? just use the 3.1 Camaro gaskets, they're thinner as well and actually fit the bore better.
ROL makes great quality gaskets, and they're good priced as well.. I'm running their .045" compressed 3.4 gasket on my 3500. Autozone can get them...

I actually thought just the 3.4's were thinner. I didn't realize all the iron head gaskets were the same size. I'll just get 3.1 head gaskets from a 90-92 camaro. Thanks for all your help

[Superdave]

I actually thought just the 3.4's were thinner. I didn't realize all the iron head gaskets were the same size. I'll just get 3.1 head gaskets from a 90-92 camaro. Thanks for all your help

I'd call ROL to verify the compressed thickness of part number HG32640HT.. That's the graphite "high temperature" gasket they offer for the 3.1 Camaro. It's probably .045".

http://www.rolmfg.com/

[TazMan]

I'd call ROL to verify the compressed thickness of part number HG32640HT.. That's the graphite "high temperature" gasket they offer for the 3.1 Camaro. It's probably .045".

http://www.rolmfg.com/

Thanks, I'll do that. Maybe the one that isn't "high temp" will be .040.

I just read somewhere that the 3x00 pistons stick out .020" higher than the iron head 3.1. Does that include the Aluminum head Gen II 3.1, or do only the Gen3's stick out that high?

[Superdave]

only the gen3 3x00 pistons pop out, the gen2's and gen1's are fine.

[ForcedFirebird]

only the gen3 3x00 pistons pop out, the gen2's and gen1's are fine.

Is it because of the location of the wristpin?

[Superdave]

Is it because of the location of the wristpin?

not sure why they did it.. maybe as a cheap way to raise compression.

[ForcedFirebird]

not sure why they did it.. maybe as a cheap way to raise compression.

I guess I was getting at weather or not the pistons are different in the gen 3, or was the deck height changed? I'm gathering parts for my new engine and don't want to make a mistake. (basically pistons are the last thing left).

[Superdave]

I guess I was getting at weather or not the pistons are different in the gen 3, or was the deck height changed? I'm gathering parts for my new engine and don't want to make a mistake. (basically pistons are the last thing left).

pistons are different, deck height should be the same.