[BruceWilkie]

Originally Posted by 65nss4spdGTO

The new IA-II iron block is cast at 9.500" with enough deck thickness to get very close to 9.200". This information is based off the two blocks I've had in the shop and sonic tested the decks.

The projected build I have for this project is right around 425ci engine with a 425CFM cylinder head.

Calvin Hill
Hill Performance
708-250-7420

Interesting Calvin... I was simming a 4.25 x 3.75 426 combo awhile back... looked very promising with efficient port very near that flow capacity.

Buildin the real thing is a whole different challenge.

Of interest... One of the better cams I came up with, the net valve seat time was the same seat numbers as the lo-po Pontiac "N" cam... No resemblance beyond that though lol! Not sure if I saved or backed up that particular file as I recall shortening the ex split some with same open point n juggling intake slightly.