Depends how much power you really need and what kind of 360 you want. If you want to just drop in a stock magnum 360 w/ stock efi, that'll be cheap and can get everything easily from the junkyard. If you want to rebuild a 360, well then for what you'd spend to do that you could purchase a low mileage takeout 5.7. For you, the electronics and all the other conversion bits would cost nearly the same between the two, maybe a couple hundred more for the 5.7 electronics than the 360 stuff scored from a junkyard, but that's a drop in the bucket. If you want to take a tired 360 and rebuild it to the 5.7's 340hp, you will spend as much as just buying a good low mileage 5.7. 5.7's with 40-80k on them are not hard to find and I usually see them on ebay for 1-2k.