Thanks for all the good info, guys. I found that to put a small journal (rare) crank into a medium journal block(With the 400 being the only large journal sbc) is expensive, whereas the spacers to put a 350 (med. journal) into a 400 block (ie 377) is reasonable. By small journal I refer to 2.30 mains and 2.00 rod journals, by medium, 2.45" mains and 2.10" rods, and for the 400 2.65" mains with 2.10" rod journals. Thanks Again for all the replies!