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1986 K2500 Sierra.

RED-85-Z51

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RED-85-Z51 Enthusiast

RED-85-Z51

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Im looking at getting a nice 1986 GMC Sierra K-2500 tomorrow. It's got 91,000 miles, no rust to speak of, Red/grey exterior, long bed reg cab.

 

Ive seen it, run it...actually put hands on it, it looks good. Has the 14 bolt Full Floating Corporate rearend, I suspect it is the 10.5" gear model, and of course the 10 bolt 8.5" front axel. NP-208 transfer Case..

 

I dont know what automatic tranny it has though.

 

The problem is, it has sat for 5 years, and now it smokes bad. I trust the guy, he says it didnt smoke when it was put up, and says the odo is accurate. Given the lack of visible wear on the interior, Im inclined to believe him.

 

It's got the 350 4 barrel engine.

 

I think it has stuck rings, honestly....

 

Anyways, he is asking $700firm, front driveshaft is off but included, and I cant drive it due to cracked nasty tires (further proof it's been sitting). He has driven it this past week on the road, but Im not that brave.

 

Anything I should look for on this thing? like hidden rust areas, frame rot, etc?

txab Senior Enthusiast

txab

Posted
Posted

Smoke is probably from valve guide seals, maybe not 100% of it. With that mileage and the fact that it has set for 5 years without running the seals are dried and cracked allowing oil into the cylinder

RED-85-Z51 Enthusiast

RED-85-Z51

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Smoke is probably from valve guide seals, maybe not 100% of it. With that mileage and the fact that it has set for 5 years without running the seals are dried and cracked allowing oil into the cylinder

 

 

im also thinking the guide seals are shot, the 350 in my vette had almost all the seals fall off it from being brittle after a quick over-rev to 6500rpms, started using some oil, but this thing is pumping oil out like a mosquito fogger.

 

Im not too worried, it's a 350 chevy...easiest engine in the world to work on.

 

Any easy way to tell a 305 from a 350?

  • 2 weeks later...
twavor Enthusiast

twavor

Posted
Posted
Smoke is probably from valve guide seals, maybe not 100% of it. With that mileage and the fact that it has set for 5 years without running the seals are dried and cracked allowing oil into the cylinder

 

 

im also thinking the guide seals are shot, the 350 in my vette had almost all the seals fall off it from being brittle after a quick over-rev to 6500rpms, started using some oil, but this thing is pumping oil out like a mosquito fogger.

 

Im not too worried, it's a 350 chevy...easiest engine in the world to work on.

 

Any easy way to tell a 305 from a 350?

 

Could be valve seals, could be stuck rings, but it could also be a bad vacuum modulator on the transmission if it's got one, it HAS been sitting five years, give it a break.....either way, not a big deal, for 700 bucks....I'd be on it like Oprah on a canned ham.

 

How to tell a 305 and 350? I'm trying to think, but I'm pretty sure about the only way to tell is by the numbers stamped in the block under the alternator....had to do that one time for one of my trucks.

 

If the frame is gonna be rusty...look at the mounts on the front of the rear springs. Those seem to be the worst and look at the frame around them.

 

Travis

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