88-98 350 into an 86

[chemsearch]

A friend of mine is getting rid of an 88-98 truck (don't know the exact year),with a 350,and i want to put the engine in my 86 k10, currently with a 305 and (i think) a th350 trans. What am i going to need to do to make this work? Should I keep the trans thats in it now, or take whatever's in the friends truck (700r4 i guess... tell me if i could be wrong)? Am i gonna run into any problems doing this swap? Thanks for any info you guys have, i just wanna get an opinion on this before i dive into it.