what is the difference between 74 and 79 frame and body mounts

[SCOOBYDANNN]

i know there is a difference in body mount bushings, so what is the difference? im thinking about buying a 79, but i already have the 74 frame fixed up and new body mounts. what am i going to have to do to make it work?

dan

 

[1979jimmy350]

the difference is in the the B pillar mounts. The 79 has a rear seat footwell where as the 74 the rear floor extends to the back of the front seats. I have had both a 79 and 74 down to the frame and the frames have different shapes in the middle section.

 

[tRustyK5]

The pre-78 K5 frames have inboard body mounts off of a crossmember where the footwell would be on later models. The frame on these rises up about 18" farther foward than the later models.

The post 78 frames have outboard mounts at the 'B' pillar that are identical in construction and elevation to the body mounts under the drivers footwell. It's doable to put an early body on a newer frame (I did that to my truck) but much more involved to put a newer body on an older frame. To get the older body on a newer frame you just need to fabricate some inboard mounts and a crossmember. To do the newer body on the older frame you'd have to section in a footwell, or run an 8" body lift...

Rene