Gror, I don't know if it will help you out any but if you have room to add an adapter you may be in luck. I was just looking @ a site recommend by a fellow in Ham Lake, Minnesota. It's called
wilcap.com they have adapters for the flat head Chrysler engine. They mention a 218, 230, & 250 Chrysler to a Chev, ford
dodge trans. I just got off the phone this minute. I was talking to Scott @ wilcap.com. He thinks he can help you out. His boss will be back in the morning. They are going to check & see if the 251 is same as the 250. Their ph# is (805) 481-7639. Do you or cranman or ted know what model trans is in there now?? Any one
got some ####'s ?