If you are wanting to lose the old dipper for a later model motor try some of the local swap meets for a full pressure 235 or 261 which is almost a bolt in swap keeping the old truck looking somewhat original. A lot of people are opting for v8"s leaving some good sixes for cheep. If your wanting the 63 or later six go for a 250 or a 292 the 194 is a real slug. I think the original 3 speed will bolt to the later hogs head but making the mounts and getting the tranny lined up the torque tube is a real bear.

ttodd's toys