http://eshop.advanceadapters.com/com...=1083637341010
is a manual for swapping your S-10 to a V-8. It tells everything you need to kow, including OEM part numbers you can use for the swap.
My son and I built an 84 S-15 Jimmy 4x4 with a 350, TH400 trans, with a B&M stage 2 shift kit.
We loaded the engine with a roller cam, cloyes gear drive timing set, with a Weiand Team-G manifold and a Carter AFB 625.