4-30-20 day for the 430 CanAm aluminum big block Chevy

[Flying Undertaker]

Originally Posted by William

I doubt any production ZL1 engine got near 575 hp. We worked with Bill Porterfield back in the '90s on a ZL1 dyno comparison. With a good tune up, open headers, no AIR pump, air cleaner or alternator it did 523 hp.

http://www.camaros.org/copo.shtml

Camaro High Performance has rebuilt several. With racing oil and modern rings, they see 550+hp.

I just had my '69 ZL-1 engine built by Brian Tilburg at Tilburg Racing in Trout Run, PA. All original 052 engine block that was bored .030 by previous owner. All NOS GM internals used, even .030 over GM pistons. Dynoed in Apr. 2019 (2nd pull) at 601 hp @ 6700 rpm limit that I had specified because of the age and rarity of the block. Brian said that the camshaft was still pulling hard, and had not reached its peak on the curve. He said it would have maybe 15-20hp more by 7300, as he had done several ZL-1's for NHRA Stock Eliminator AA/SA cars before. Race break-in oil and modern rings used. I have both dyno sheets. Same conditions as one stated above; good tune up, open headers, no air pump, no air cleaner or alternator!