Head gaskets

**tthrash** · 11-25-2009, 12:50 PM

I am in the process of replacing head gaskets on my 98 WS6. I had been losing antifreeze and idle was erratic so after a few tests I decided it was time to dive in. I have 225 AFR's the previous owner had installed and found out the bore of the gasket was too small, causing the leak. I ordered a set of cometics before I looked up what gasket I should use. I am now selling those by the way. Sfter comparing prices I decided to go with GM MLS gaskets. How many have used these and what do you think about them? How well would they handle nitrous? I am sure this problem existed when I bought the car, from the looks of the overflow tank the previous owner put some stop leak in it to mask it. I should of caught it anyway but I am using it as an excuse to put a convertor in while the headers are out. Let me know what ya think.

**402 Guru** · 11-29-2009, 10:17 AM

cometics are the way to go they will last to hell and back . i was going through redline runs at the dragstrip and i still have the same cosmetics on my trans am 402 and now its my daily driver which it is going purring like the day i built her you can drive without knowing you blowing out a gasket. what are your mods

**bills98ta** · 11-29-2009, 01:46 PM

I'm 14:1 CR with cometics And run over 7k all the time !
Main thing you need to know, is how far the piston comes out of the block at TDC. Mine came out .010" then I ordered .050" thick, to get a .040" - .045" quench... This is important when ordering head gaskets.

**SOMbitch** · 11-29-2009, 03:15 PM

Originally Posted by bills98ta

I'm 14:1 CR with cometics And run over 7k all the time !
Main thing you need to know, is how far the piston comes out of the block at TDC. Mine came out .010" then I ordered .050" thick, to get a .040" - .045" quench... This is important when ordering head gaskets.

The block/head finish needs to be a little better with a Cometic too.. Ra 30 IIRC....Been a while since I ran them....

**tthrash** · 11-30-2009, 09:08 AM

Originally Posted by 402 Guru

cometics are the way to go they will last to hell and back . i was going through redline runs at the dragstrip and i still have the same cosmetics on my trans am 402 and now its my daily driver which it is going purring like the day i built her you can drive without knowing you blowing out a gasket. what are your mods

Stock short block, HCI( afr 225, xfi comp cam, ls6 intake), SLP exhaust with long tubes, SLP ram air with smooth bellow, HP tuner, full BMR adjustable rear suspension, currently on the car. I am installing a 3500 and a set of 1.7 roller rockers. I hav ethe upgraded spring and don't want another rocker coming apart.