Help finding a replacement engine

[bwl101]

Hi all, I just recently acquired my grandfather's 1972 C10 Long Bed Stepside. It came with a 307 from the factory, but it is toast. It was parked at a family member's house after an engine issue and sat for years with one of the heads off. Looking for another 307 or 350 that's running that is also inexpensive as for now I just want to get it back on the road to make sure every else is still functional and with being on a tight budget. It is a no power steering, no power brakes, no AC truck. Was thinking more on the 350 side as it should make a little bit more power than a 307.