I agree with Fitz. If the funds are tight, you can usually find a good running truck or even a motor on craigslist for 500-700, don't waste your time with parts store engines.
I sold a 4.3 to a customer when I worked for Checker, he brought it back twice, the first time there wasn't an oil pump in it, the second time it leaked from everywhere. Not the kinda thing you want from something you just spent 1300 on.