Join Date: Jun 2011
Location: Colorado Springs
To the question of could it be rebuilt, I would say, sure. To the question of should it be rebuilt, I would say, probably not.
The Pontiac 455 really wasn't a great engine for performance. Most Pontiac guys want a 400 or they REALLY want a 428. (Yes, Pontiac made a 428, but they put it into only a few cars like the Catalina.)
The vast majority of 455 engines were just luxury powerplants; big, but not necessarily fast. (There's something about them that Pontiac guys don't like. Perhaps they're not very durable?)
While you certainly could build a 455 Pontiac into a bruising, stump-pulling torque monster, I'm not sure it would be worth it. Older Pontiac 400s are pretty plentiful. And stroker kits are readily available for those engines.
If you have a Pontiac in which you want to install this particular engine, I think you'd be better off finding something else. Unless your 455 is an HO example that came out of a Trans Am, it's likely not worth a costly rebuild.
FYI, as I understand it, when it comes to older, Pontiac V8 engines, there is no "Big Block/Small Block". They're all the same block. But there are Big Journal and Little Journal examples.