How much will it affect compression going from the stock .054 gasket to a .068 on a LS1 5.7? I thought it was 1 point but want to make sure.

 

It is less than a full point but not much. It isn't a very good idea to lower compression this way since you will be increasing the quench area and raise the probablility of causing a second ignition to develop and travel in the chamber towards the air gas mixture. Two better ways are to get pistons with reliefs or get heads that have bigger combustion chambers. Some head porters can also open up the combustion chamber for you but I would leave that as a last resort.

 

We are actually looking at this for a temporary fix till AFR's come out.The car is 10.8-1 and installing a Blower.I can tune the high compression if I have to.