Ftyler,
I have to tell you right up front, I am an automotive machinist and generaly I tell people to have a good shop do an engine for them, BUT the engines from GM are hard to beat for the price. I would advise you to make sure that they are new engines and not remanufactured (I think GM sells both). I wouldn't touch the engines from e-bay, some may be really good but you can only look at a picture and guess. If you go the machine shop route, go to some events or the drag strip and ask who guys like in your area. Go talk to the shop foreman and look at the shop if you can. The good places won't be the cheepest but they will be there if you have questions or if you need somthing in the future.
Hope this helps.
Sean
