I need a bbc gen 4 block, with 4 bolt main.

Steve

Not sure if you know, but GM now makes a replacement 454 block that can accommodate the old heads, crank and rods, or the Gen 5 & 6 parts. We have such a block in our race boat with the guts and heads of a Gen 4 motor. It does require the Gen 5/6 oil pan and timing cover. It works great. If you need it, I can get you the part number.

I have a gen 4 4 bolt .040 over and I have a 2 bolt .030 over also have square and oval port heads