I Am so happy to finally be a K5 owner. I justused it u picked up a 1972 K5 Blazer with a three on the tree in a 307 cubic inch engine and it only has 65,000 original miles on it no rust.
Is this a rare truck because of options nobody wanted and low milage or should I build it up?

 

I guess it could be considered rare as I've never heard of, let alone seen, that drive train on any K5. Does it make worth more? That's the question. Its your truck, I say do as you please. Did you buy it because it is a "survivor?" Or did you buy it to build it? I guess it also depends on how much you paid for it.

 

If it's pristine and all original, you may want to preserve it that way. Personally, I would probably build it into what makes me happy (which would most likely be a big-block with an SM465 and NP205).

The 307 isn't quite as bad as a newer 305, but it's not great.

 

AJBert, thanks for the reply. Ah, therein does lie the question. I paid 20k for this truck in hopes of building it up. But with only 65k original miles, 3 on the tree with a 307, NO Rust, hard top never taken off, body in great shape, I need to find out if these options, low milage, and good condition is worth a lot more as a surviver.Do you have any idea where I can find a good source for production numbers of K5 Blazers?

 

This is the best I could find online: 1972 Chevrolet Blazer technical and mechanical specifications (conceptcarz.com)

Might want to call up a dealer or two and see if they can help. This site doesn't list the 307 option for V8's, though. If it is stock and the site is correct then this has turned into a head scratcher for sure.

 

I say build it the way you want it and keep the original drivetrain around for the next guy if there ever is a next guy.

As far as the engine goes, the 307 was the standard v8 with the 350 being an option. I would bet that the combination in your truck isn't as rare as you would think. The fact that it still in there is probably what could now make it seem rare.

The links below is to the original 1972 tech & sales brochures from GMHeritageCenter.com and Brochures.Slosh.com: