[Bill Hanlon]

Originally Posted by Tom Vaught

1) sorry for the confusion, Bill. Would you agree that the 455 SD Block has a larger distributor hole machined into the block and you need a distributor housing "sleeve" to run a conventional Distributor Gear and Conventional Camshaft? Not a Pontiac SD Expert by any means like Tom S, but assumed that the 455 SD camshaft and the 455 SD Distributor Gear were a matched set. And I assumed that when I wrote the post that Pontiac Engineers put a different configuration (sized) gear on both the distributor and the camshaft to handle the higher pressure 455 SD Pump.

What am I missing here? Why recast a new Pontiac block with a different distributor installation hole size for no reason?

Tom V.

I'm the dummy here. Just trying to learn. Seems to me that if you made the distributor gear larger, you'd have to make the cam gear larger to keep the 1:1 ratio required of the gears (same number of teeth on both).