Frozen Block

Gotta ask, what is a 230 block?
I dont see any sign of rust in those bores. I bet it spun a bearing on a rod and seized up. Have you unbolted all the rod caps you can get at?
230 is the last three digits of the casting # of the (supposed) most desirable 400 block, to build a stroker with. Has the most metal in the bottom end.