you can fix the gen the thing is there is a reason cars haven`t had gens since the early 70`s......they require more maintenance. The ACdelco will go in with minor mods (enlarge botom hole of alt and use washers to line up pulleys, ant the top mount belt tensioner can be bought off the shelf or be made by bolting 2 belt tensioners together (the span is a little longer than usual though pickups often have quite a long tensioner assembly. Finally have run Bosch and ACdelco alts in many cars over the years and I prefer acdelco, bosch alts are less reliable and more expensive/harder to repair. Usually I am a big bosch fan and will always pay the extra for the quality but with alts it doesn`t work.