I ended up buying a 235 that was already out. The two bus engines looked ok but the guy never would give me a price. One of those we will work something out deals. The one I got supposed came out of a 51 3100. But numbers on block f55y seems it was originally a 55 year power glide engine. I hope to tear it down this week and see what's inside. Block number 3836233. The plan is to build with one piece rear seal and try to get compression up to at least 8-1 ratio. We will see.