Originally Posted by LATECH
Dont spend money on roller rockers. They wont do anything for performance on a street build.
The 78 block is most likely the 557 block. It will be an OK block, but if your building in excess of 400 horses the older block would be better.
If it were mine, I would sell the 557 as a buildable core, and use the money to get what is needed to put the other one in the car.
Pontiac, having had block failures, went back to the #488986 block in early 1977, I believe. This block would be fine for a build-up. I would recommend checking the casting number befor doing anything.