Changing from a 2.3 liter to a 2.9 liter on my 1988 Ford Ranger?

O.K. so here's the deal. my current 2.3 (4 cyl) liter has a loud knocking noise coming from it and not able to find the source without tearing tearing apart the head and block, I have found a 2.9 (6 cyl) in same year and model truck, I need to know what else I should pull off the wrecking yard truck in order to for the 2.9 to work. My truck has a 5 speed manual transmission with TBI ... The wrecked truck had automatic trany with TBI...and they only want $55.00 for the engine. please help me out.