Got my first GMC today.

[RED-85-Z51]

I got a 1986 K2500, Long bed Reg Cab, 350 engine.

It's got 96,000 miles and looks it too. Original 2 tone red over grey.

It's been sitting a while, but the seller drove it 20 miles to my house. Seems to be running on 6 or 7 cylinders, and runs rich, also has no guts at all.

Still has the original cat and it's noisy, exhaust is a wreck.

The front diff I have no idea what it is, but the rear is a legit Dana 60/8 lug.

Ill post some pics in the morning, Ive got a ton of work to do on it, all new exhaust, install front driveshaft, rebuild the Q-jet, or drop on a new Holley. Ive got a Lunati Voodoo 60101LK cam kit...

But the most troublesome problem is this...

This morning I brain farted and hooked up my batt charger up backwards to the batt. for maybe 10 seconds. There is a plastic/rubberish block on the top of the firewall, to the rt of the wiper motor...it has 2 posts on it, and 3 wires. One of these wires started smoking and burnt in half. I assumed it was fusible link and I installed in inline fuse holder and a 30amp glass tube fuse. My problem is it seems like the fuse blows when I turn the engine off, and once it blew without turning the engine off.

Is this possibly a bad ign switch? or something? should i just take the fuse out altogether?

[RED-85-Z51]

I apologize...I have been liead to by the previous owner. Id never seen a D60 before and he sold me on the large rearend being a D60. I just pulled up some diagrams...it aint no D60, it's the stupid Corporate 14bolt..but not the good one, it's the Semi-Floater 9.5" model. I confirmed it has 14 bolts, oblong cover, etc..

The front, I was told was a Dana 60, but it was obviously smaller than the rear, and I assumed it was a D44. Nope..stock weak corporate 10bolt.

So in short...it's got the stock running gear.

I was planning on 35's with a 6" spring lift...but no way a 10 bolt will take 35's.

Ive got a goo mind to post the previous owners home and cell numbers on a site I heard of...let them blow up his phone for a few days. I hate liars, and this guy was a Certified ASE master Tech, so he knew exactly what he was selling.

[CLASSIC87']

Not for sure if this will cool you down... but I ran 35's on a 10bolt suspension for years... I personally never had a problem.

[79gmcclassic]

[RED-85-Z51]

Originally Posted by CLASSIC87'

Not for sure if this will cool you down... but I ran 35's on a 10bolt suspension for years... I personally never had a problem.

Really?

Hmm. I was told the D44 was the bare bones minimum to run 35's and the 10bolt seems weaker than any D44.

[CLASSIC87']

In my experiences I had no problems... I ran 456 gears in the stock 10bolt rear/front as well.

[RED-85-Z51]

wow!

How about the TH700R4...Im split.

The one in my 85 vette has 155K miles on it, tons of burnouts, donuts, all running a 2100 rpms convertor..and when the 350 engine blew at 155K..the trans was still chirping the 1-2 shift with sticky 10" wire rear tires.

My cousin has a 1990 Sierra Z71...30 minutes in the mud and a new 700R4 bit the dust...

[CLASSIC87']

I had the 700R4 rebuilt and added a corvette shift kit in it as well...

[RED-85-Z51]

Got another question. The grille has a couple slats busted out, the band of plastic/rubber trim around the body is falling off or peeling up, and my metal trim peices are rough...anyone reproducing this stuff?

I think I can salvage the "K2500 Sierra" mody badges if those are non-existent.

[bikes&bowties]

I have offroaded 10 bolts with 35's fairly hard.. no breaks yet of my own.. but i have seen it.. I have also seen dana60's break. although the one i saw was running 44 boggers... but still everything breaks...

[RED-85-Z51]

cool, Ill just have to run it and hope it all holds up.

Last ? for the evening.

When I got it, there was gas in the RH tank, but not gas smell or any smell from the left tank. The selector is on the RH tank..and the truck does have a slight tendency to lean to the RH side, like it hasnt really ever had to use the LH tank.

How can I test the switch and see if it is working? Is there like a solenoid somewhere I can also test for function? Ideally, Id like to be able to top off both tanks...thats like what..40 gallons?

Ive GOT to find a haynes manual for this thing...it's got serious underhood wiring issues, and vac issues.

[RED-85-Z51]

People who restore these models....who is the #1 sourse of parts?

[48cj2a]

I ran 36" to 40" tires back in the day, my ony problem was rear ujoint failure during the 38-40s phase on a GMC Jimmy.

I only had 3.08s too so it was quite a pooch but I was young, dumb, and full of **** so it was all fun.