I prefer the rebuild but my point of view comes from having rebuilt engines before, here in Ky you can get good machine work done still reasonably. I search Ebay for some real deals and have really saved myself some money. You can customize your rebuild with the exact camshaft and carburation package you want. In addition, greater satisifaction and having locals or close to locals doing your machine work makes them responsible for their craftsmanship. If you just want a generic motor or short block thats ok I suppose, especially if your not wanting much build up in performance other than carburation. I just would wonder who would stand behind those crate motors........the people who sell them to you are just wholesalers who buy and simply reselll. Will they take much interest in you if something goes wrong. LIke I said you can bargain on Ebay where others have started projects and lost interest and they sell brand new components sometimes 60 cents on a dollar. I just recently purchased all new 440 steel crankshaft, Ross Pistons, new rods with high strength bolts, all clevite bearings (victor series) incl cam bearings for $1300. He had $1900 in them and purchased it from 440 source and lost interest and bought a Mustang.........so I did well. Where the largest potential for error is purchasing bad used equuipment and not having good machine work done and rotating assembly balanced. Dont get to rushed to purchase anything less than what you need.