'72 K5 - Greg's "Might As Well™" Build - UPDATE - 2022.05.03

[Greg72]

My original plan was to just rebuild this one fairly conventionally.....leave the 1-Ton axles and leafspring setup, then add the new driveline (502BBC/TH400/Atlas-4). Throw in a rollcage and call it good.

The '69 K5 was going to become the "Transformer 1st Gen" project....with fully removeable body panels for wheeling, full tube chassis, King coil-overs, 4-link, Mog axles, Viper 6-speed, etc.

The problem is that I have too much guilt about cutting up that perfect '69 tub just to use it for that. It really is too valuable and clean. The '72 is a much better candidate for cutting up, since it's got quite a bit of rust in the lower areas anyway....and the amount of modifications I want to make will be extensive. Might as well use the '72 as my "transformer" vehicle!!

I'll most likely just sell the '69K5 and use that money to help complete this one. The costs are going to be high enough to complete a single K5.....let alone TWO of them. Some of the work I'm doing will ultimately get re-done (like the step when I finally transition from TH400 & 1-Tons to the T56 and Mog Axles), but in the long run it seems smarter to focus my attention on the one vehicle and do the "Phase 2" upgrades after I've had some time to enjoy this first build up.

There is also the practical consideration of space. My manspace is bascially a single garage stall (for now) so unless I want to wait another few years to start my build.... the '72 gets the nod for the upgrades and build-up.

 

[BUDDY]

While I love the direction & attention you are giving this build, IMHO it would not be in you're best interest to try & adapt a Viper T-56 6-speed to this application. That transmission is awesome & bulletproof...... for a Viper or any other car. It wouldn't fair well in a fullsize truck I don't believe. Let me back up my opinion -

1972 blazer GVWR 5500 lbs
2000 viper CURB wght 3380 lbs

I think the biggest thing though is the close ratio of the tranny. Even with the low gearing of the mog axles & doubler, the low-low-low gear final drive would be - 7.56x2.66x1.96(np205)x2(np203) = 78.83

Although you would be able to drive it on the freeway a lot easier in 6th. Maybe that's more you're plan.

Synchronized in all gears, electronic 1-4 skip-shift and reverse lockout mechanisms
Gear Ratios
1st 2.66
2nd 1.78
3rd 1.30
4th 1.00
5th 0.74
6th 0.50
Effective Final Drive 3.07
Overall Top Gear 1.54

Go here for Viper Specs.

I'd still recommend a NV5600 out of a duramax or new cummins though.

http://en.wikipedia.org/wiki/ZF_S6-650_transmission

Later,
Buddy

 

[Greg72]

Buddy,

Well that's not a good apple-to-apples comparison....the axle gearing in the truck will be a LOT deeper than it is on the Viper, AND the transfercase is going to help build the power further downstream than normal also. BTW -> The calculation should remove the NP205/203 (no doubler) and replace it with a 5.44:1 Atlas4. I think you'll find the crawl ratio is a LOT sexier....

Ultimately, the ONLY transmission option that works is the T56. Nothing else has a 50% overdrive, and anything less will be unacceptable on the highway. Rocklin Standard Gear offers some beefy upgrades to the T56, so if by some miracle I manage to break it in "stock" form I still have a way to beef things up further.

 

[BUDDY]

I knew you'd have some pretty good reasoning behind it. JMHO. No biggie.

I didn't catch that you were running the atlas, but the crawl ratio didn't look terrible anyways. 109.4:1 is better though.

I seem to remember a guy on pirate a few years ago who reversed a NP203 range box so that it would provide his overdrive. Pretty much he'd shift the NP203 into "low" gear for cruising around, & when he neede the deeper gearing he'd just shift back to the "high" range. He had mog portals also.

In either case, you'd have to have some kind of custom adaptors made up. Also, I don't remember ever hearing back about how well the range box held up running in "low" all the time.

Just another thought for ya'! This would be one of my dream iterations for my own blazer. Of course I'm looking up the hill at what you currently are running right now, so I'm already jealous!!

Later,
Buddy

 

[Greg72]

I seem to remember a guy on pirate a few years ago who reversed a NP203 range box so that it would provide his overdrive. Pretty much he'd shift the NP203 into "low" gear for cruising around, & when he neede the deeper gearing he'd just shift back to the "high" range. He had mog portals also.

Yep, that was a K5 called "The Hulk".... I did some reading on that one, but the catch as I'm sure you already figured out is that the overall length of the boxes gets REALLLY long (especially with a Doubler).... I was dubious about the use of a backwards 203 from a gear noise and reliability perspective also.

It's going to be a long and lonely road ahead for this build. I can't say I've seen 1st Gens with these sorts of goals and objectives before....so I'm breaking a lot of new ground.

 

[Greg72]

2008.01.11 - Morning Update...

UPDATES AND FRESH PICS!... 2008.01.11

There has been steady progress since last time.....here are a few shots and descriptions of what's been going on (or more accurately, coming off!)


I got the interior of the truck cleaned out so that I'd truly be working with an empty shell. Got tired of tripping over jackstands, wiring harnesses and other remnants of the '67 Burb teardown that I was storing in the bed of this K5. I also pulled off the driver's door, the flaps for the fresh air system and an overlooked radio bracket:

Next up was a big one. I have been wanting to remove the 2" body lift from this truck for a long time, and decided that it was finally time to do it. I had to remove the rear bumper (which had been bolted to custom bracketry to compensate for the body lift), and cut off the upper shock mount in the rear which was also blocking downward progress. About half of the body mount bolts came out cleanly, the rest fell victim to the cutoff wheel and hammer.

I decided to do the actual lowering one side at a time. It seemed like a more gentle way to do it and prevent tweaking the body....especially with no doors and lots of rust. Here's the end-result.

BEFORE:

AFTER:

Now the frame rails are just about even with the outer rocker panels and the truck is a lot easier to climb into. The rear tire clearance is now laughable...so I'm going to have to do some more serious trimming if I want it to ever flex again. When I finished with this step, I also decided to remove the remaining exhaust system, the transfercase crossmember and that small side anchor that bolts to the NP205.

Now I've got a good size pile of "FOR SALE" stuff going....

Flowmasters
TH350
NP205
Crossmember
WTO Hydro Assist setup
AGR 2WD Steering box (for crossover)
And a sweet 2" Body Lift

Next steps this weekend will probably go back to the tedious paint stripping process to finish off that windshild frame and front firewall area. It won't be long now before I need to start cutting out bad metal and start welding in new patch panels.

 

[Yukon Jack]

Not a bad parts pile, out to make a little money from that stuff. Do you have a target date for completion? I had one with the K20 and missed it due to body shop jail. After that I decided it would get done when it got done and that was good enough.

 

[Greg72]

YJ,

Well.....as you well know the "Might as well..." expression can really change a completion date!!

I am really encouraged by how quickly this project is moving with respect to the teardown, and I am pleasantly surprised by how little rust (relative term) exists in the windshield and other areas. I definitely have rust repair to do, but it's not an intimidating amount, and I feel confident that it's within my capabilities.

The rub, is that it's not going to be a "stock" restoration so it's not as simple as 'replace-bad-part-with-good-part' for a lot of this. Each step requires me to think about the end-result and if there is something I need to do to accomodate my transformer chassis idea.

I'm so far into this build, that I've already decided to do the rear 4-link (with King coilovers) as part of this phase....that adds complexity, but also $$$....so part of the problem is going to be if I can earn the money I need as fast as I'm spending it. (I don't have a good feeling about this one! )

So basically, I should probably budget at least another month for body modifications and rust repair....then start working on all the tube chassis stuff (which could easily take a couple months).... once it's all set up correctly, it gets blown apart for bodywork, powdercoating, galvanizing, plating, chroming or whatever... I'm hoping that by doing as much prep work as I can in advance, the time it spends incarcerated in "paint shop jail" should be minimized.

If the money holds out....and I get lucky with a paint shop (aka VTBlazer) who can schedule me in on short notice.... this thing might be running under it's own power some time this summer????

 

[vtblazer]

I'm almost speechless at your progress but truthfully not all that surprised being this has been in the works for years. (in your gray matter at least)

I once had a guy say to me,
and I'll pass it on to you..."your like a hobo on a ham sandwich" the way your diving in!

Parts wise, I replied somewhere that I was interested in the cross over and the fan set up...remember?

 

[Greg72]

Parts wise, I replied somewhere that I was interested in the cross over and the fan set up...remember?

They're yours if you want them....I have the feeling you and I will be "trading" some parts in the coming days/weeks anyway.

 

[Burt4x4]

Damn Greg
Crazy man!
My body could use a good strip down and rebuild...my floors are slowly being ate away by cancer...so when your done you can come out to Cali and do mine next K! hahahaha
Good Luck and keep the pics commin!
Burt

 

[vtblazer]

They're yours if you want them....I have the feeling you and I will be "trading" some parts in the coming days/weeks anyway.

Absolutely, just wanted to make sure they stayed around.

 

[Greg72]

MORE PICS 2008.01.13 (SUNDAY NIGHT):

 

[Engineered Vintage]

Wow - you don't mess around - I had to do several double takes on the top picture to figure out what I was looking at.

I've never seen that vent from this side - LOL

 

[AJs72K5]

Took me a second to figure it out too. Are those the "pine needles in the cowl" I'm seeing around the vent in the top pic??

 

[bp71k5]

I still can't figure out what the third pic is. it looks like the driver side floor, but i don't see any dash or firewall above it?

 

[vtblazer]

I still can't figure out what the third pic is. it looks like the driver side floor, but i don't see any dash or firewall above it?

It's REALLY apart now!

That third pic is the back side of the firewall on the drivers side lying on the floor.

Can't wait the see the "full view" pic of what's still there. (not much I'm guessing)

 

[Greg72]

Don't panic.

That last shot isn't the "actual" floor....it's a section that was cut out of the '67 Burb. It's layed across the front framerails as a workbench so that I can steal metal patches from it for my floor repairs.

The left side "Sharpie" markings are for a patch that will allow me to remove the tweeter pods that had been fabricated into the floor areas on both the driver and passenger sides. It was a good idea for sound quality, but a tough environment for speakers due to water and dirt.....and I have come up with a more elegant way to achieve the same effect now that the truck is completely blown apart.

Yes, those are pine needles in the cowl and that is NOT a staged photo. In fact, before I cut that outer cowl skin off I used my shop vac to really clean inside those spaces to see how effectively I could remove debris. The flexible hose with no attachments was pretty easy to stuff way down in there to get the dirt and leaves, but couldn't get those twigs out (obviously). The more I see the resulting rust damage from those cowl vents, the more I loathe them.

Astute viewers will also note that I now have a set of door braces welded to factory hinges and strikers. That made a dramatic difference in the strength of the front windshield/cowl area. It used to move quite easily if I tugged on the upper windshield corners, now it's solid as a rock. Clearly, if you want new sheetmetal to fit correctly (and don't want the body to sag when the old metal is cut out) door braces are a critical item to bolt on BEFORE too much cutting has occurred.

 

[Yukon Jack]

Dang, give Greg manspace and he blows his K5 apart!!!

Are you worried about flash rust on that exposed metal?

 

[Greg72]

I need to do more research on what types of coatings are appropriate for the inner panels specifically to treat and prevent rust. I need something that can be welded, but that also reacts with existing rust and neutralizes it. Also in some cases, it needs to be able to accept a topcoat of paint. My understanding it that certain things like POR-15 can't be painted afterwards?

Eastwood has a bunch of things:

Rust Dissolver
Rust Converter
Rust Encapsulator
Cold Galvanizing Compound
Heavy-Duty AntiRust

The immediate concern is being able to treat interior panels that are about to be closed-up again. Outer surfaces that might re-rust will eventually get sandblasted before final bodywork, so I'm not overly concerned with those now.