Differences noted between 1970 and 1972 body tubs
 

I am in the process of a restoration of my 1970 Blazer. Unfortunately, the body shell was absolute rotted trash, and I was able to salvage a bit from the original body shell, such as the entire dash frame assembly, the floor hump, and drivers side B pillar. The frame was surprisingly good, with 2 very deep and clear partial VIN numbers. I am also salvaging the front clip sans the radiator support.

Anyway, my donor vehicle is a well worn but never salted 1972 Blazer that I purchased from Arizona over 20 years ago, when Blazers were still reasonably priced. It had light accident damage on the passengers side bedside requiring full replacement, but great floors and rocker boxes. The outer rockers were junk, so I replaced them with GM parts.

Here is a small list of differences noted between the two model years:

• The passengers bucket seat floor catch is in a different location and different design. There is a special reinforcement bracket bolted to the RH rocker box and also spot welded to the floor pan to support the floor catch area.
  
• The passengers side front seat belt retractor is mounted to the bed floor horizontally on the 1970. The 1972 is bolted vertically to the riser.
  
• The very most rear outer bed sill has the cutouts for the 1972 only frame.
  
• The accelerator pedal designs are totally different. 1972 is cable, 1970 is rod. I am sticking with the 1972 cable system.
  
• The rear seat bolt pattern is in different locations between the years
  
• The gas filler neck area cutout on the inner LH bedside is totally different, and the 1972 floor has the large hole for the vent pipe.
  
• The 1970 filler neck is multi piece and is a vented to atmosphere design
  
• The inside rearview mirror is mounted to the windshield on the 1972. 1970 is screwed to the upper windshield pillar
  
• Also, the brake lines are totally different front to back, requiring a different frame hose bracket, frame clips, and brackets on the rear diff. I am switching to front discs from the donor 1972, so I went with a 1972 brake line kit.
  

Re: Differences noted between 1970 and 1972 body tubs
 

I've had several 70s and I had one with the provisions for the rear top hold down and the other one didn't. The hatch hinge area was also different on both of them. One had plugs the other had the large plate, I'm talking about on the top side
I don't remember what was on the hatch side.

Re: Differences noted between 1970 and 1972 body tubs
 

Both of my tubs had the nutserts in the bedsides for the rear top bracket.