I have a 86 Chevy 4x4 1500 with 6.2L and 4 spd standard. I would like to convert the granny low 4spd to a HD 5spd with an overdrive. Which GM 5spd will work (I heard the New Venture 4500 does) and is the a direct swap in or does it require an adapter of some sort? Any advice is appreciated....thx