I am finishing up a 383 LS build and looking for head gasket advice. What does everyone recommend. Engine will have CNC ported 243s on top.

Thanks!

 

Not enough detail for nobody to help you out.
Pump gas ?
Have the heads been milled any?
What pistons you using ?

 

Sorry about that. Here are some more details.

Yes, 93 pump gas primarily.

Not sure on amount heads were milled, I assume very little. They are 243 casting heads ported by Frankenstein a year or so back.

Pistons are Mahle. They do have valve reliefs, but I don't recall the exact -cc amount. I believe they were the closest to being flat top though when I had my engine builder order / install them. I hope this helps clear things up a bit. I can take some pics if necessary.

Thanks again!

 

It really doesn't clear things up any at all. The valve relief could be -3 or could be more....
Milling the heads go make a difference also on what thickness head gasket you'll want/need to get the compression you want for your motor.

 

This has been an ongoing project which I have switched parts and paths on a few times since it has been sitting taken apart. I had these heads done before choosing to pull the motor and go the 383 path. At that time I was attempting to go about as high of compression as I could on pump gas. So I think I remember being told these heads would have put me at about 11.7 : 1 on the stock LS1 motor / pistons. So in that case the stock 243 combustion chamber is 64cc, I assume these may be 62-62.5 cc .... So I feel like stock thickness head gaskets may be a conservative approach considering a tiny bump in compression from the decking, and slight decrease in compression from the valve reliefs? What brand / material if that is the case, would be optimal?

Any additional ideas or advice would be appreciated.

Thanks

 

Never used head gaskets to adjust compression. The tiny amount of change you get won't matter.

However, you should use the head gaskets to set piston quench. A tiny change here can make a big difference in efficiency and performance. You'll need to know piston to deck height to know which gasket to use.

 

I am only somewhat familiar with piston quench, but have a basic understanding. What would be optimal?

 

Most engine builder say 0.040" is perfect for a street car. Some people here say you can go as low as 0.035".