Just curious whats the most HP you have seen out of a 525 without using a supercharger or turbos? I went down to bare blocks and am almost done putting them back together with some goodies. Dyno runs will show if it was work it or not

We found really good gains with the 525 just by going to a big bore. With no other modifications other than a 4.600 bore and ECM tuning to correct air/fuel we picked up approximately 60hp over a stock 525. Final number on the dyno was 610hp. Stock 525s constantly make 550hp on our dyno. By no means claiming to be the highest number from a 525 but we were very happy with the gains

I stopped reading after this because you clearly don’t like to party.

Thanks for the reply. My motors went on the Dyno Thursday. They’re now 514ci. New heads, bigger valves, stiffer springs, better rocker arms etc. 657.2HP at 5750rpm and 641tq at 5000rpm. This was with a carb setup so when I put the efi intake back on the numbers will orobobe a little lower. Going to need to tune ecm like you did. Unfortunately I need new headers as fell so this rebuild is going to cost more than I was hoping lol

Pic from Mark Rinda at MER Performance in SC:

I gotta say, I love seeing “blue power” in colors other than blue. I wish more folks would have opted for that upgrade. I always wanted to build a pearl white 37AT with one red motor and one blue one.