Alan I put a 235 in a '33 truck which is basicaly the same as the 29. I had to change the crossmember at the bell housing to one from a 37 truck, other years of the era would probably work.
The 29 engine is longer then the 216 or 235 so I had to modify the front mount to support the engine. I don't know what you intend to do with this truck but if it is not going to be driven a lot I think I would just try to rebuild the present engine.
Good Luck
Cleon
