Triumphant Return

[RotaryRocketeer]

Alright, “triumphant” is a stretch, but I’m returning to the forum with a completed swap. After moving twice, having my built motor filled with non-potable water by some overzealous firefighters, endless nonsense with a garbage driveshaft guy, and countless other setbacks, it’s done-ish. Behold. My 1976 GMC with a fresh 470 lbs/ft carbureted LQ4.

Did some interior refresh while it was down, dash LEDs (which are awesome and dimmable), new gauge lens, etc. The usual.

Edit: Fixed photos

[RotaryRocketeer]

Various stages of the build.

[RotaryRocketeer]

Couple more mid-process pics. This was where we started getting close enough to inspire motivation. The swap really moved fast once it got to this point.

[RotaryRocketeer]

Brakes failed on a quick run into town the other day. Like, the kind of failure that puts a pinch mark in the seat. The truck and I were both lucky there was no traffic. Turns out the soft hose to the rear axle split and was leaking like a bucket with no bottom.

Popped a new master cylinder in it ($25 is cheap insurance,) and ordered some braided hose. They shipped FedEx, so god only knows when they'll show up. Did some doctoring on my shift governor as well as replaced the modulator while I was in the neighborhood. Wideband is getting powered up tomorrow morning when my dad comes by. I'm trying to make the guy a believer in modern electronics.

And please don't judge based on how dirty the engine bay is. That outside work is not appealing right now.

[jjzepplin]

Looks good so far. Keep up the good work! Welcome back. Are you replacing the fronts as well?

[RotaryRocketeer]

Originally Posted by jjzepplin

Looks good so far. Keep up the good work! Welcome back. Are you replacing the fronts as well?

Thanks JJ. These things are never REALLY done, but it's getting closer all the time. 400 or so trouble free miles out of the drivetrain now. Only problem has been the brake debacle.

Replacing the fronts? As in?

[RotaryRocketeer]

Dad dropped by the shop today, but was in hurry and didn't stick around, so we didn't really get much done together. He did bring me a nice surprise though!

[jjzepplin]

Nice wrenches! I was talking about the front soft hoses. My daughter had a 2006 Malibu that the front caliper locked up on. Caliper was fine. The hose going to it was bad. That was a couple years ago.

[RotaryRocketeer]

My bad. Definitely. I ordered a full replacement kit, so all three are getting replaced whether they like it or not. Hard to believe the difference that a set of braided steel hoses can make. This is my only driver that didn't already have them.

[RotaryRocketeer]

Got all my brake parts last night and got to work on it today. Naturally, the nut on the hard line to the rear end rounded off. It was enough to aggravate me to the point that I moved on to something else. My kickdown port had been leaking and I repaired it with a new cable end housing. Dropped the pan to make another linkage rod to replace the old chewed up one too. At least that went off without a hitch. It’s late enough now to start drinking these frosty adult beverages and call it a day.

[RotaryRocketeer]

Got everything back together for a leisurely evening rip around the county. Brake hose job went smoother after letting the fittings soak in PB overnight, got my kickdown cable all adjusted and mounted to the manifold, new LS3 belt tensioner installed, and was able to use my new Motive bleeder (pretty cool after you throw away the lid fasteners they give you and use C clamps.)

Then things went south in a hurry.

Trans somehow lost 90% of its fluid within a half mile of leaving the house. Which of course meant no more go. But it did downshift and rev out to 5600 or so before that happened, so I know my kickdown install and governor weight swap worked. Silver linings.

A real nice kid gave me a ride to the house (didn't take my phone) to get the tow rig. Didn't even wave him down, he just stopped and offered to help. Living in the country has it's perks. And all I gotta do for him is let him drop a line in my pond every so often.

Some days you win, and some days the lord presses his giant sandal clad foot upon the windpipe of all your dreams. Today was a sandal day.

[jjzepplin]

Oh gosh! I hope your trans is ok!

[RotaryRocketeer]

Originally Posted by jjzepplin

Oh gosh! I hope your trans is ok!

All is well. Got to poking around under there this morning, and it’s pretty clear that the 1-2 accumulator assembly shot out the side when it kicked up to 2nd. Gonna go out there and try to find it in the ditch. There are two more TH350 cars in the shop to rob parts from though.

[RotaryRocketeer]

And lo, the lord felt bad for being kind of a dick the previous day, and thusly, did smile upon him today. Can't believe I found all this in an overgrown ditch. Just had to find the spot where she started dropping fluid and start searching.

Couldn't find the spring or the retainer ring/clip or whatever it's called. No worries.

[jjzepplin]

MAN you gots some good eyes and tracking skills.

[RotaryRocketeer]

I was surprised to find anything, but I'll take the compliment!

[RotaryRocketeer]

You don't see too many of this kind of post here, but I wanted to add it to my build thread.

Turns out the dually is pretty darn quick! It blew the doors off of a G body El Camino with bolt ons from a dig and roll, a 2003-ish Mustang GT from a roll, a 2015 crew cab 5.3 Silverado with intake/exhaust/tune dig and roll, a twin turbo Infiniti Q50 dig and roll, and put a half a car on a 2017 twin turbo Ford Raptor from 65-triple digits! Can't help but be crazy hyped about my build and combo. And I still haven't hooked up the wideband and tuned fuel or put a stall in it!!!

All aforementioned activities performed by professional drivers on a closed course.

[RotaryRocketeer]

Finally got around to halfway cleaning the engine bay. Needs paint on fender tubs and some touch up here and there. Clean though!

[RotaryRocketeer]

Add a 2005 Joe Gibbs RCSB Silverado to the list. This combo is surprising me every day.

[jjzepplin]

I am sorry. What does all the jazz mean?

[RotaryRocketeer]

Just me getting excited about how well the truck runs, acting like a hooligan all over the countryside and racing anyone who will give it a go.

I knew it was going to be a good running setup and do everything that a truck should, but didn't think it was going to be anywhere near as sporty as it turned out. It's almost bordering on legitimately quick. Going to take it across some scales tomorrow, but it's gotta weigh 5,000 lbs.

[RotaryRocketeer]

Chopped the headache rack off of the bed yesterday and I'm pleased with it. IMHO, it takes it from hay hauling truck to a more muscle-esque vibe. May not be for everyone, but I really dig it. Also scraped off the cowboy stickers on the back window. Headache rack had prevented that previously.

[jjzepplin]

What trans and rear ratio do you have? Sorry if I missed it.

[RotaryRocketeer]

Short tail TH350 and peg leg 3.73, for now. Trans has been doctored up to handle the abuse with extra clutch packs and all that jazz. There's a 6L80 or 90 in the works for the near-ish future.

[jjzepplin]

Did you upgrade the internals of the LQ4?