Compression / 400 SBC

[Z3PR]

Just a question for future ref. : Soon or later I will rebuild the 400 SBC in my 76 Blazer. I've always raised the compression in all my motors. I only run premiem gas (91 oct). How high of compression can I go ??? Will it be good for a 4x4 ??? Most my street cars are around 10 to 1 on pump gas, with no problems.

 

[Sandman]

I run 10:1 in my 400. I also run a longer duration cam that somewhat helps this. I also run only 91 oct and can get away with around 8 to 10 degrees of timing. When I mud race, I ussually buy a few gallons of racing fuel and run 12 degrees of advance. I also live at an elevation of around 5000 feet. When I drove it to the Californian coast, It started to ping real bad and I had to lower the timing down to get it to run ok.