Something else to consider is the floor in your truck now. I had a 32 ford come into the shop before needing a new seat. I found the metal in the floor to be to thin to support the seat correctly. The owner didn't want to get into putting another floor in so what we did was build a frame for the seat out of 1x1 under the car and welded it to the frame. Then made new brackets for the seat which lined up with the new seat frame underneath the car. The owner was very impressed with how much sturdier the seat felt and it made a real clean install, even from under the car.

__________________
gotta love a pro street