engine questions

i am about to start getting my engine ready to go back in, but i have a few questions b4 i do. i am working on my 1994 gmc sierra 5.7 350 auto trans. i have a crate motor from my 1984 chevy pickup. from what i am told these are two different motors but are both 350's. i know the heads on the 84 are different and am thinking if i get vortec heads and a vortec intake that it should work?? will the transmission from my 1994 work with the engine from my 1984??? is there any reason this wouldn't work??? thanks, any help is appreciated...