Undecided on what to do with newest truck?

[PushnFords]

Background: I came across a lady that said she had a couple broke down vehicles in her yard and was planning on scrapping them. I ended up paying $90 for an '88 C1500 with a 5.7L and drove it about 15 miles to a gas station. Wouldn't start after that....it is hydrolocking on a cylinder. Basically the truck was owned by her grandfather so it only has 98,000 miles on it and rides/handles really nice. But the engine is shot and the tranny didn't have reverse. I'm picking up a good engine/tranny with 88,000 miles tomorrow and I'll reseal both of them before installation, tune up, fluids changed, new exhaust, etc. The cab and front clip are straight and rust free except for the cab corners and the hood is red. The bed is pretty rough with rust above the rear wheels and both sides are dented.

What does everything think the truck would be worth after I do the mechanical repairs...leaving the body as it is?

How about a value if I put on a rust free bed I found, patch the cab corners, and paint it?

Thanks!

Derek