I take back what I said a few months ago about the 4.250 stroke motors not making good power as mine did not at the time and I hadn’t seen anyone else impressing me with one. I am now impressed with the output of the 511/512 combos. You guys are making good power and going impressively fast with them. I found a key ingredient in the 511 combo, compression. I gained almost 4 tenths with a 1.25 point increase also tightening up the quench to .040 at the same time.