?s about the drivetrain

i own a mazda and want to do a 4.3 swap so i figured this is the best place to look for tech help. my questions, will a five speed tranny bolt up to an engine that came from the factory with an automatic? Also what is the rear end from an s-10 or blazer good to? if it can go 300 then im good for a while but if not then ill go for a ford nine inch rear. thanks for the help.