Unless you are going for serious horse power, it wouldn't matter if you went with a 2 or 4 bolt main. Generally, if it came from the factory with a 4 barrel carb, chances are it has a 4 bolt, when dealing with V-8's from the 60's and 70's. That's not always the case but it's a good way to weed out the 2 bolts. And feel free to ask about V-8's whenever you need to. I'll answer any questions that I can,
Scott
