Another 72 Build Thread

[Another 72]

Hello all! I've been trolling the forum pages off and on for a while now, ever since before I even purchased my 1972 K5 Blazer. I've managed to garner a little knowledge off the site - which is saying a lot for me - and I figured it was time to give back a little. I know how much everyone loves a good build thread, but welcome to mine anyway. LOL!

Still reading? Well, let's start from the beginning. First of all, like my yet to be introduced K5, I'm a 1972 model myself, so I guess I have an illogical affinity for my 1972 K5. At least the later models tend to be better equipped, i.e. front disc brakes.

I joined the Air Force in 1993 and was stationed at Malmstrom Air Force Base, Montana. Wonderful place, cool job fixing communications gear out at the (then) 220 missile and missile control sites. My 1968 Mercury Cougar wasn't much good in the winter, and an ochre 1972 with a white fiberglass top and 235/75/R15 "baloney skins" (bald tires) on the used car lot for the lofty price of $2500 caught my eye. Remarkably, it was still there after hunting season, so I stole it for $1800. The one below isn't mine, but the one I used to have looked a lot like this:

[Another 72]

After nearly ruining the truck with a budget 2-inch add-a-leaf, a 3-inch body lift, some white wagon wheels, and some 35 X 12.50 BFG All Terrains, it looked a lot like the truck below. I probably should have re-geared it and retired the old 307. Keep in mind I was a young airman at the time bringing home about $400 every couple weeks. I soon got the bug for extended cab, super cab, and crew cab full size 4X4 pickup trucks, so the Blazer had to go. I sold it for $3500 and have always regretted it. Again, the truck below isn't mine, but the stance is very comparable.

[Another 72]

Over the past 20+ years the Air Force has taken me all over the world, and I've owned a lot of cool old rides. After the K5 Blazer, I owned a 1979 F-250 XLT Ranger Supercab 4X4, a 1978 XLT Ranger Bronco, a 1973 Bronco, a 1971 Wagoneer (transplanted onto a shortened 1984 3/4 ton Suburban frame), and a 1967 F100 stepside (2wd). Along the way my old bright red 1968 Cougar was totalled by a half-blind old man driving a yacht, and I more or less lacked the heart to take on an old car again, but I did let a 1968 XR-7 "hangar queen" take up space in my garage for the longest!

Eventually, I'd had enough - I HAD to right the wrongs and get another old K5 Blazer, and in November of 2015 I purchased one on e-Bay. It was in South Dakota, I'm in Virginia. But before I could take delivery I had to sell the 1967 F100. It kept the wife happy...little did se know that I had already purchased the K5...but I think she figured it out when the K5 showed up in February of 2016. Here's my 1967 heading to its new home:

[Another 72]

Below is my 1972 K5 Blazer as it looked when I took delivery in February of 2016. Its a North Dakota truck (I think I stated South Dakota before), so rust is manageable. It had a homemade 1/2 top with a sheet metal wall welded in behind the front seats - those were the first to go.

[tjsblazer]

I'm in for the ride. Looking forward to another.

[Another 72]

Thanks, Jeff. My build isn't going to be anywhere near as detailed as yours, not yet anyway.

The first thing I did with my Blazer was lose the crappy, homemade half-top and sheet metal wall behind the front seats. Now I wish I would have kept the front part of the half-top - I saw a thread on here recently where someone used the front of the top to attach soft top snaps without drilling the windshield frame. It looked a little odd but was probably great at keeping out leaks and precluding a PITA soft top/hard top transition.

Before I ditched the half-top, I located a usable fiberglass top in southern Pennsylvania - it's a double-wall so it's a bit heavier than I the single-wall was on the Blazer I had in the 90s. Then again, I was 22 years old back then.

I didn't trust the bottom wall of the top to hold the top down if I ever got the Blazer up to speed with the windows down, so I drilled holes in two pieces of 1/8" thick, 3/4" wide, 3-ft long steel on each side with 3/8" nuts, bolts, and oversized washers underneath (grade-5 or maybe grade-8).

On another note, the bedside holes didn't line up properly, leading me to think my truck originally had a single-wall top. Then again, I may have read somewhere that trucks assembled at different plants might not have had the holes in the same location, but this seems unlikely as the original hardware (heavy captive rectangle nuts) was more or less permanently attached. I'm sure someone else here knows way more about that.

[tjsblazer]

I too think that holes should align regardless of the Assembly line because of the top.
Double wall tops have the nuts in them bolting up through the bedside so from the factory the truck bedside was drilled with holes only.
Single wall tops have holes only bolting down through the top in to captive nuts welded on the the underside of the bed rail.
Since in '72 they used both the double and single walls some Blazers from that year have bedsides drilled for both.

[Another 72]

Like most of us, I'm not 20 years old anymore, and the idea of climbing in and out of a truck 7 feet tall with 35-inch tires isn't nearly as appealing as it used to be. Plus, I'd like this thing to be HALFWAY practical again. So, off come the 8-lug 3.73 or 4.10 or 4.56 or whatever geared Dana 60 full-floater rear and Dana 44 disc brake front, probably from an early or mid 1970s Chevy 3/4 ton. Hint, hint - anyone interested in these axles? Anyway, the spring pad width matched my Blazer. I think the rear is also wider than original 12 bolt rears, so they position the rear wheel nicely to match the front. I never noticed on my old Blazer 20 plus years ago, but the front axle is 4 inches wider than the rear, meaning the rear wheels sit 2 inches inside the quarter panel relative to the fronts.

I sourced some original 6-lug axles - a GM 12 bolt rear and a Dana 44 front - from a fellow forum member - thanks Dwayne! I haven't verified yet, but they're probably the 3.07 3.08 geared axles, which is okay because I'm currently running the granny-low 4-speed. The plan is to eventually swap in a 5.3 (or 4.3 EcoTec) with 6-speed automatic which will keep my 1st gear ratio at 12.4:1, which I think is good for stock height, 31-inch tires, 250-300 horsepower, slightly more torque than HP, in a vehicle weighing nearly 4,000 pounds.

I know what some of you will say, but I'm interested in hearing OPINIONS on this.

Great website for gearing calculations:
http://www.grimmjeeper.com/gears.html

[Another 72]

Thanks Jeff, that makes way more sense. By the way, I like daydreaming about fabricating an aluminum top after I'm done with EVERYTHING else (which might NEVER happen). I guess I better hurry up on this build - if I'm going down THAT road I better do it before I'm in my 70s!

[Another 72]

Hmm....going back to the Grimm Jeeper gear ratio calculator, I can see some 3.55 gears in my future. I think that would match extremely well with 300 HP, 300+ ft/lb, and a 6l80 in a 4,000 pound vehicle. This line of thinking occupies WAY too much of my processing power!

[Another 72]

The first big step in the build was to replace the 4' lift springs with original height springs from:

https://www.truckspring.com

Original GM 12 bolt and Dana 44 from a 1st gen part out - thanks Dwayne!

And these 17" Vision rally wheels:

[Another 72]

So, I pulled the K5 into the garage (my son pushed the garage door up some) and it looks like the first thing I need to do is remove the ridiculous bumpers to give myself room to do the axle swap.

Here's what I'm dealing with:

[Another 72]

And this:

[Another 72]

I might have been wrong about the lift springs - once I got the bumpers off I think they were actually 6 inch springs! That metal is about 3/8" thick!

Whoever built and installed these bumpers definitely wanted them to stay there. I had to hack the front off, but the rear bumper - which doubles as a COMPRESSED AIR TANK - came off in one piece if someone is looking for something like it.

[Another 72]

So with the rear end barely in the garage, time for the suspension and axle swap.

[Another 72]

All right, so the front mounting point on BOTH rear leafs was a complete PITA!!!

I wish I had pictures, but I was so pissed off I probably would have smashed my phone. I ended up taking an angle grinder and a few cut-off wheels to hack the front spring eye to bits. So much for selling the springs!

So, not my first time replacing leaf springs - that's easy. But this was my first axle swap. I gotta say, this part was a straight-forward bolt-on affair, which is GREAT considering the replacement axles cam off another 1st gen Blazer!

After I got everything bolted on, new rotors, wheel bearings, calipers, pads, hubs in the front; new drums, wheel cylinders, shoes, brake hardware, and 2" inch spacers in the rear; I thought the truck sat a little high. Sorry, no pictures. The replacement springs had 6 leaves in the rear and 3 in the front; I seem to remember my old Blazer from 20+ years ago having only two leaves in the front and maybe 5 in the rear, so I removed the middle leaf in the front and the second from the bottom leaf in the rear stack. I don't know if I'll drive it around like this, but I like the stance. Maybe the springs will settle. I also installed Monroe shock absorbers installed (#34944 in front, #34822 in the rear). The shocks allow about 3-4 inches of travel each direction, so I should hit the bump stops (going down) before the shocks bottom out. The wheels are off the ground before the shocks expand all the way.

Here's the new stance - it's about 7 or 8 inches shorter now, and it's the perfect height for me to get in and out (I'm 6' 2"). There's about 7 inches between the tires and wheel well.

Note - It's been in the garage a couple of weeks and boxes are already settling on it - I better get moving on this thing!

[Another 72]

I was able to re-use the rear driveshaft, just had to press in new u-joints: a 1350 at the case and a 1350/1310 adapter u-joint at the axle. Next post - bending and flaring my own nickel-copper brake lines in the rear (another first for me).

[Another 72]

Oh, I almost forgot - the most painful part of the build - selling my XR-7 roller to make room for the Blazer build - I HATE townhome living! At least I have a garage.

Now you're all caught up - time to start the build thread. But first a moment of silence for the project I never got to complete - a rust-free California 1968 XR-7. Good luck with the build, Trey.

[DeadheadNM]

I'm on board! Any chance you overlapped with a colonel Keen while in MT? He may have been retired by 93. Pete

[Another 72]

Pete,

I don't know, did he have a daughter?

I was there from 1993 to 1996, but to be honest I tended to steer clear of colonels back then!

Rob

[DeadheadNM]

Lol! He did. He's my uncle. Eager to watch your build. Off to a great start Rob.

[DeadheadNM]

All 72s had provisions for both single (caged nuts) and double wall (holes) tops. If your blazer was a St Louis build its very likely it had a double wall top: early Flint built K5s had 2x wall then Flint switched to single wall.

[Another 72]

Good to know. I removed the caged nuts - most of them were falling out or severely rusted anyway. I think I had to drill some holes for the doublewall, but maybe I just expanded the holes.

[Another 72]

No wrenching today, but I did purchase a good, clean OEM grill and OEM hood, as well as some Goodmark inner fenders. Monday morning I'm picking up OEM fenders and OEM core support. Monday afternoon or Tuesday morning - depending on family plans - I hope to dismantle my 1972 front end sheetmetal. Or maybe I' should finish bending, flaring, and installing the rear brake lines, bleeding the brakes, sealing the rear diff, adding gear oil, and driving around the neighborhood (no bumpers).

Decisions, decisions!

[Tom Vogel]

Those new wheels look nice. Someone is sure to want those slots though.