Will the bottom rear seat out of a 4 door 88 fit into a 2 door car??? How about the top part of the seat will it fit also.

 

As long as it's from the same body style and compatible year it should be a slam dunk. What year is your 88? You could probably also fit rear seats from a 98 into your car if you wanted.
If you're trying to fit an 88 seat into an A body I don't think you'll be able to do it. Different interior dimensions.

 

Yea both cars are a 68 delmont 88. I'm going to look at a car in Ohio and if it turns out to be the same color interior, then I'm going to get as many things as I can. Small items mostly... rear view mirror, kick panels, steering wheel, gear selector needle,wheel moldings, clock light wiring harness,and what ever else I can. This car is in a yard that only deals in GM cars from what I'm told. I'll take a lot of pictures, especially Oldsmobile.

 

the rear seats should be identical. i have a 66 dynamic 88 ragtop with the rear seat out of a 4 door...no problems...same speaker in the seat as well