DSOMZ51

There appear to be several bore sizes to choose for a Cometic H/G with 0.040" thickness. For example, for Cometic P/N C5751-040, it lists a 4.060" bore and 0.040" thickness. I believe I have seen other 0.040" Cometics with a 4.030" bore size but can't seem to find that P/N right now. Should I go with the 4.060" or other recommendation to be used with a set of just purchased Trick Flow 220 As Cast heads (un-milled)?

berk4422

Considering heads myself, interested to hear about you gains. Sorry, but can't help on the gasket.

DSOMZ51

I am anxious to start the build and see the results as well! Still waiting for cam, rockers, and other parts to arrive.

JohnDaMan

https://www.texas-speed.com/p-2260-cometic-mls-cylinder-head-gasketls1-engine-4030-bore.aspx

There you go

DSOMZ51

Thanks, JohnDaMan! The TSP part number ends up being H1295SP5040S which I used to search forums and found some threads regarding quench possibly being an issue with 4.030" bore size because of the piston coming above the deck anywhere from .005"-.007". Also, the gasket P/N H1295SP5040S seems to come up a lot for LS1 heads. However, it appears that the GM head gasket replacement part of 12589227 has a bore size of 4.020" so the TSP part number should be good. Just trying to make a good choice.. Anyone else have thoughts on this?

JohnDaMan

You're good, the LS2 is a 4.00" bore

DSOMZ51

Awesome. Thanks! Your feedback and other research I've done seem to suggest I'll be good to go with this one. One more part list off my build!

meinersk

I was just told for my z 06 take out cometic because they fail and get oem and do cutting on the heads...This by a huge corvette moding company that used to use cometic all the time...I think mine is leaking with 16,000 miles on it