[boodlefoof]

Hi everyone,

I recently purchased my first Pontiac project (a '63 Tempest) and am trying to finalize the plans for the build of the drivetrain. I have a Ford 9'' with 3.89 gears that will find its way to the back of the car and am planning to go with a 4L80e in front of that. For the engine, my current thought is to build a stroked 3'' main motor (still considering 4'' v. 4.25'' stroke). My hope is to build a sleeper car that will be well into the 11s (or better?) in the quarter mile.

I've been looking locally (southern Maine) and have found a couple of mid-60s 389 blocks and a couple of 400s, but all of the 400s I've located thus far are the later 70s 500557 blocks, which I have read are not the best option for a high performance build. I'm trying to figure out whether or not I should keep looking for a non-557 400 block, or whether I should just go ahead and pick up one of these 389s.

Are there any significant differences between the 389 and 400 blocks that I may not know about (I've done a number of Chevys, but this is my first Pontiac build) that would be a big factor here? Is the ~.060'' bore difference a real potential limiting factor (for larger valves, etc)?

Any and all thoughts are appreciated. Thanks guys.