if it is a 1950 235 it will have a lot of the same parts as the 216, so might be worth keeping around for the time being. the Leveler that hoyt talks about is a great tool to have around, I picked one up at Harbor Freight pretty cheap. The Hi-Torque(Low pressure 235) is a nice engine, performance will be close to though. It should use the same water pump if it is a 1950.
I would run the engine serial number to make sure.
One thing I told a friend that was debating rather to rebuild his 216 or find a later 235(post 55) was that the cost to fix the 216 would be expensive, but to find buy and then rebuild a later 235 would be about the same, plus the cost of the new engine.
In your case if you have to find a trans, and the pre 55 235 is in decent running shape, then it might make since to drop it in as is and get some miles out of it before rebuild to save some money(especially since it has the working trans).
Both the 216 and the early 235 are tough engines that often get a bad wrap. Just think of the boys in WW2 driving chev and gmc army trucks across north africa in high heat with all the dust and sand(let alone combat) and those trucks made it, so as long as you have good oil pressure and and you keep the rpms within acceptable levels the engine will last quite awhile.
sorry to ramble, my $.02
