Cometic head gaskets... .040 vs. .045

[silverTA2002]

I just got my heads cam package in the mail today.

TEA 1.5 5.3 heads milled less than .005
Comp cams 220/224 .581 114lsa +2
Trick flow chromoly hardened pushrods (7.4)
Cometic head gasket .040


I was wondering if this was the right gasket. Most people seem to be using .045. What difference will it make?

[silverTA2002]

Also what will my compression ratio and P/V clearance be?

This is for a daily driver.

Will I be better off mailing those back and getting GM gaskets locally?

[ws6_nightcat]

you can download a compression ratio calculator online, if you want pm me and i'll give you the site. further more, your headgasket thickness plays a major factor in your compression ratio. more compression can equal more power. a lot comes into play with that though. anyway. figure out your compression. get a good set of sce gaskets at the thickness you need and have fun. the sce titans are the best i've seen but they're pricey and may be overkill for your needs. i'm not familiar with cometic headgaskets so someone else will have to chime in to tell you if they're good or not.

[WALLst AL]

The .040 will give you a little higher compression over the .045. Cometic gasket can be reused and they have a tighter squench than the GM gaskets.
Since I milled .040, I went with the thicker .045.

You can figure your compression ratio here

c5frc.com/calculators/Compression_Ratio_Calculator.htm

[silverTA2002]

Well, I kept them, Install went great, car runs perfectly fine on 93 octane with my 11.3 to 1 compression.

I'm very happy so far. Under 2k, it's just like stock, above it, the car really wants to take off.

[WALLst AL]

Well, I kept them, Install went great, car runs perfectly fine on 93 octane with my 11.3 to 1 compression.

I'm very happy so far. Under 2k, it's just like stock, above it, the car really wants to take off.

cool