what should the compression be on this sled thanks in advance

Depends on the ring-seal. We always took enough off the heads to give us .072 squish using the two L-shape pieces parallel to the pin method. With a fresh, tight motor you should run at least mid-120's with the motor broken-in, warm, throttle tied open(ignition disable of course) and at least 10 rips on the cord to get a good test. They'll survive on junk Minnesota gas at .072 and be close on the piston wash if you run the gas chip.