'72 GMC K25 build 454/4L80e

[superchevy]

Hi Guys,
I have had several requests to consolidate my K25 build posts into a single build thread, so here we go. I originally bought this truck 3 years ago while I was working on my '55 Chevy gasser (build thread here: http://67-72chevytrucks.com/vboard/s...96#post4324396 ).
The truck had been purchased by a friend of mine who had started to do a little bodywork for paint...that's why my first pics of the truck show it partially disassembled in the paint shop.
The truck had already had a 454/700R4 combo swapped in.
I got the truck over to my shop, and decided to do a full frame off resto with a few upgrades and color change.
Here are a few pics of her when first bought and the most recent.
I have hundreds of pics I will post in the coming days that follow the complete build from frame and suspension mods...drivetrain mods...to body mods.
Casey

[superchevy]

First things first. Time to pull the 454/700r and clean and paint the frame. I used Easy-Off oven cleaner...about 6 cans...sprayed one evening and let it soak on the frame overnight. The next morning I broke out the rubber gloves, a BBQ pit brush/scraper, and scrubbed the livin' crap out of the frame. After the scrubbing, a quick hose off with water, and dry with an air hose, I was ready for primer and paint.
I have had frames powdercoated in prior builds, but I went with good old Rustoleum on this build....I wanted something I could apply in the barn, and easy to touch-up if scratched. I used several cans of Rustoleum Rust Converter as a primer...2 good coats...then followed with about 3 coats of Rustoleum Satin. I like the results.
Here's some pics of pulling the 454/700r:

[superchevy]

Here's some pics of cleaning/painting the frame:

[superchevy]

Some of you sharper eyed readers might have noticed that before cleaning the frame, I had already installed the suburban gas tank and the DIY 4x4 front engine crossmember.
I'll cover those items here.
The suburban tank I bought off ebay. It required a little cutting/welding before it fit properly.

[superchevy]

DIY 4x4 crossmember

[STOCKISH]

Sweet! Love it.

[superchevy]

Time to rebuild the front and rear suspensions.
I installed a 4" front and rear spring lift kit from ORD...Off Road Designs. It uses new springs/shocks for the front suspension, and a shackle flip kit for the rear suspension to achieve the 4 inches of lift. While I had everything apart, I completely rebuilt the front and rear steering and braking components using stock GM components as well as a Superlift raised steering arm.
Also, I rebuilt the front and rear differentials. The front diff is a stock DANA 44 with 4.10 gears. The factory spicer lockouts were broken, so I installed new WARN lockout hubs.
The rear diff is a factory DANA 60 with 4.10 gears as well. The rear leaf pack is huge, and has a factory swaybar attached...a heavy duty towing setup for sureEverything was removed, sand or media blasted and primed/painted with Rustoleum satin black.

[ItsRandy]

Were there any crossmember modifications necessary to mount the rear trans mount? I'm using a 4l85e in a 69 C-10 with a ZZ-502 and was wondering about crossmember placement and trans mount.
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[superchevy]

The trans crossmember had to be moved rearward due to the longer length of the 4L80...not hard to do.
I should have moved the DIY engine crossmember forward an inch. This would have given me more room for the HEI to clear the firewall...as it is now, the HEI is very close to the firewall...even with the 2" body lift.
NOTE: I tell everyone thinking of a 4L80 swap that I would seriously think of using a T400/GearVendors set-up instead. If I had to do it over again, that is what I would do. When you factor in the cost of a rebuilt 4L80/converter/stand alone computer/harness...you are right at the cost of running the gearvendors, and it has 6 speeds and is rated at 1200hp. Plus you don't have to deal with programming issues, etc. Just my 2 cents.
Here's a shot of the assembled drivetrain in the frame.

[c10seconds]

Looking great! What are you you planning on using to control that trans?
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[superchevy]

Now the frame, steering, and suspension are mostly done, lets look at the metal work that was done to the cab. I needed to replace both rockers, both cab corners and most of the floorboards and toe boards. How I wish those 1-piece replacemant floors were available 2 years ago when I did this, lol.
Here's some pics:

[superchevy]

more

[superchevy]

Now it was time to break out the sand blaster and strip the cab, doors, and core support.

[72chevyfleet]

that is my dream truck a nice looking clean 4x4 i would just drive it because it looks cool

[mjensen]

That looks awesome! It has the exact same stance as I would like with mine. Great job!

[FRENCHBLUE72]

Awesome looking truck it came out very well... Whats the total build time?

[superchevy]

Thanks guys. It's been 4 years of off-and-on work. I haven't done much since this past Spring because it's just been too damn hot. I did get out there yesterday and today to install a new tierod centerlink...the old one had a slight bend in it and was causing some alignment issues...MUCH better now, and today I installed some 6 degree axle shims in the rear to correct a slight pinion angle vibration...again, much better now.
I snapped a couple of pics of her sitting there in all her dusty glory.
With the alignment and pinion angle issues corrected, I can now take it out on a long shakedown cruise...hopefully at least a 100 miles or so. As it is, I've only put 31 miles on her so far in some shorter runs around the neighborhood.
Sorry about the pics...it's hard to photograph in the dark barn.
Just a couple very minor things to do now.
Casey

[superchevy]

Well I finally got a chance to take the K25 out for a long drive. I washed the thick layer of dust off...her first bath by the way...and took her for a nice 35 mile run through the back country roads to Wimberley and back to the shop. Wow. What a difference in steering and handling that new steering link and alignment made...very nice. She rides so smooth, and loves 70-75 mph on the freeway thanks to the 4L80 overdrive.
You might also notice I put on a new set of black step bars. I didn't like the small aliminum steps that I had installed...they looked to dainty for such a big truck.
She still hasn't gone a 100 miles yet, lol.
Here's some pics.

[superchevy]

more

[mjensen]

I love the look of that truck!

Great job!

[71sierragrande]

Unbelievable!!!!!!

[Mr Chevorlet]

I can only say one thing. BEAUTIFUL BUILD and TRUCK

[CHEVY072481]

what stand alone computer harness do you use fo the 4L80E/np205?
I would like to use that setup on my truck.

[superchevy]

Well, the last test drive revealed that the rear end gears were shot...the high-pitched whine was a dead give away, so after some more testing and confirmation, it was time to install some new 4.10's and a new TracLoc posi unit. I am lucky enough to have a good friend who sets-up rearends all the time, so I bought the parts and he did the install.
There's not any pics of the set-up as I was out of town during the install and my buddy didn't take any snaps. He left the rear open to show me the test pattern on the gears and backlash, so I do have a couple of pics with the case spreader installed.
Here ya go: First pics are of axles pulled, draining the rear end gear oil, the case spreader installed, the new 4.10 gear set and TracLoc posi installed, and the rear end cover reinstalled.

[72LSK10]

Sweet looking K25, I love the way these trucks look in black.