302 built with 9-1 compression, forged pistons and HEI distributor. Engine is in a 1951 GMC 1 ton firetruck and the rear gears have been changed to 4:11 instead of 5:14 with stock Muncie 420. Motor kept having oil leakage issues from the rear main but was redone and placed back into the truck. It still leaked but not as much and ran really strong for 26 miles then…….
Guestimate is excessive timing and too much compression for the weight of the vehicle.
Fixed he distributor to limit total advance to 32 degrees instead of 50 +
Cut down the forged pistons to reduce compression.
