So I have a 96 gmc k1500 with the vortec 305. I recently saw an add for a 98 vortec 350. The problem is it has a rod knock according to the seller. He also said there shouldn’t be any cracks in the block it’s self. He is selling it for $100 and I was wondering....

1. Is it worth it to buy and rebuild it? (A friend will be doing the work on it not me but his prices are good)

2. Would I be able to use parts from my current 305 to rebuild it? Or are they different?