My 350 crank is looking pretty shot. I have a fresh block that my parts guys gave me after it's owner never paid the bill, but I still need a crank. I have a nice one from a 305 that will fit, but it's a one piece oil seal. I know GM makes an adapter for one piece blocks to go to two piece cranks, but I need the other way around. Anybody got any info on this? How about a two piece crank for the old Gumbster?