[mrennie]

Back at this, and have collected all the parts to build the motor this winter.

Build will be a 400 block, 4.250" forged stroker crank, SM 72cc heads, Ross .040" dished pistons (dish still to be determined), forged I beam rods, Bullet SR cam 255*/263* @ .050 on a 110 LSA with .605" lift.

I have two 400 blocks I can use, both cast # 481988. One is a 1971 and the other is 1973. I looked them over very well before picking one to send to the machine shop, and upon visual inspection, it looked like the 1973 block would be better. I will post some pics to show the differences, then get to the sonic results.

First thing I noticed was that the 71 block did not have the "00" casting in the valley, where the 73 block did. The pic on the left is the 71 block.