1.) Is there a head gasket for aluminum heads with a compressed thickness between .041 & .051?

2.) If not, which would you go with for a high performance street car?

.041 = 10.2 Compression ( Octane problems?)
.051 = 9.96 Compression

 

My fault...I didn't account for the smaller bore of the .051. The .051 gasket gets me 10.02:1 CR which is good for me. The only thing I guess I would ask now is...is the 10.23CR too high for 93/94 octane?

 

On aluminum heads? No.

 

I really dont think you will run into issues at 10.2 with aluminum heads. Use premium, be happy.

 

The stock Vette L98 aluminum head head gasket is .051" compessed. Ask for a set of gaskets for a '90 - '91 Corvette at your local Chevy dealer.

Back in '91 the part number was: 14088948

RBob.

 

You're certainly going to be right near the edge. But with good tuning should be ok. Select a spark plug that is slightly cooler in heat range than what the stock corvette L98 motor calls for. A non projected tip plug helps too. Give the motor no more timing than it needs. If 32 will do it use 32deg.

 

It would be helpfull if we knew what cam you were using. The static compression is less important than dynamic. Are you stating the dynamic compression?