86 GMC High Sierra

andrewbr · April 24, 2005

Hello all, I'm new to the forum and had some questions for you guys.

I'm generally a Ford guy, but I recently saw a GMC pickup that really caught my eye. It's a 1986 GMC High Sierra 1/2 ton (Regular cab long bed) with a 305 in it. It's also got a 3-speed automatic transmission with overdrive (that's what the owner told me, anyhow) and is 2WD. The body is in great shape, no rust, and only one even mentionable dent. The interior is looking nice as well, though the truck is without a radio.

The guy is asking $1,500 for it. Apparently he picked it up at the Volunteers of America so he could move to a different city, and he no longer has any use for it, so he's trying to get rid of it. I was just hoping that you guys could offer your thoughts on this truck, such as on the price.

In addition to that, the truck has the infamous saddle tanks. I understand they can be slightly more dangerous than say a gas tank mounted in between the frame rails, but I also hear it's a bit of an exaggeration. Anyway, would it be practical to remove the saddle tanks and mount one between the frame rails?

Thanks to all who reply in advance.

-Andrew

Cheekster96 · April 24, 2005

Hello and welcome.

I have an 87 Chevy 3/4 ton 4x4 with the dual tank set up. Never once have i had a concern about driving this truck or getting hit on the side by someone and worried about a fire bein caused. As long as the tanks work and the switching valve works, i would leave that design alone.

The 305 is a dog, especially with the carb. I think power output is at 160 hp or close to that number.

I didnt know the half tons came with a three speed auto, usually it is a 700R4 4 speed. Maybe you have the TH350 tranny (light duty 3 speed). The TH400 (HD) were reserved for the heavier trucks.

My truck is old and a bit beat up but has never once let me down. I have pounded it, beat it and used it to haul heavy loads, go camping in, pull a boat and play off road, not once has it not gotten me home. These years of trucks defines what a truck should be.

Hope this helps some.

Lee

mmmikkke · April 24, 2005

I owned a 86 with dual side-saddle tanks. At the time of the "news" story about this design, I was very interested in the safety issue, but didn't really feel I was vulnerable in normal driving. But I knew immediately that my resale value was hacked. Your post, 10 years later, is proof of that.

So I critically analyzed the NBC assertions about the safety of these trucks. I even had the videotape that Ford put out as Detroit recoiled in disgust at what NBC did to mislead the public about the dangers posed by this design.

I decided that all we really had here was a tightening noose of expectations by the public. GM was the last holdout on side saddle tanks. Of course, now that another 10 years has gone by, we have even higher expectations, and the utility of our vehicles is somewhat diminshed as a result. Witness the smaller tanks, and the unavailability of the dual tank option.

But back *then*, GM asserted that these vehicles were safe, when used as directed, when not driven "damaged", and when not suffering from severe corrosion, and most certainly when not driven with incindiary devices (model rocket engines) aimed at the fuel tanks while a 45 mph vehicle targets the sweet spot of the truck from the side. (That's exactly what NBC did, and GM proved it!)

There was one thing I remember about this design that might matter to you. The tank(s) are designed to have an air space at the top of the fuel load. So when you fill your tank, stop filling when the nozzle clicks off. Don't trickle in another gallon or two.

That air space is part of the design of these trucks that helps absorb the shock of a side impact without rupturing the tank(s) and permitting fuel to spill.

Hope this helps.

andrewbr · April 24, 2005

Thanks for the reply. The guy who is selling me the truck may have meant 4-speed including overdrive, but I'm not sure. As I said I'm usually more of a Ford fan, so I'm a bit slow when it comes to figuring out which transmission is which. I also managed to figure out the milage, kind of anyway. All I could see on the odometer was 09025.8. The door was locked and I couldn't see the first digit.

As for the tanks, you make a good point. It's unlikely that anything bad will happen. Think about it, it's not very likely you'll get in an accident. Then, it's even less likely that you'll get t-boned or suffer some sort of hit that will get your gas tank. And even less likely is a spark or something else igniting the gas. You're probably more likely to get struck by lightning than burn up because of a faulty gas tank.

R Dogg 56 · April 24, 2005

Edited because I didn't properly read andrewbr's first post at the top.

Well then, I hope that, in the event you decide to purchase it, you have a lot of fun with it. 1500 for it sounds like a deal. Good luck.

andrewbr · April 24, 2005

Thanks for the welcome , but I just want to clarify something. I'm currently not a truck owner, I'm just asking some questions on a truck I'm looking at buying. I was wondering if the price is right and such, as well as what needs to be done to it.

mongo5888 · November 22, 2010

I have a 1986 GMC High Sierra 1500 with the "Rally Sport" trim package that has been in my family since it was almost new. It has been worked hard it's whole life and has been very reliable for my family before me and now myself. The little 305 and the 700R4 have held up fairly well and I have had plenty of power there when I needed it. The stock 305 is no powerhouse, but it nonetheless has enough grunt when you ask for it and if you feel like doing a few modifications such as a better flowing intake, pulling the smog equipment, some headers and some better plugs you can REALLY wake that little mill up. My truck also has the saddle tanks and the only problem I have had so far is with my fuel gauge/sending unit working erratically in it's old age. $1,500 sounds like a pretty decent deal if it's in really good condition. All in all my truck is the reason that I am a GM man through and through, and will be for life.

My baby is in the shop at the moment getting another engine dropped in it. The hard worked 305 turned over 276,562 and finally broke two connecting rods (it's an old truck, don't do 90 for extended periods of time. LOL!) It has been overloaded, pulled trailers, raced numerous times, loaded down with branches, rocks, gravel, dirt, engines and parts, rotten fruit...anything you can think of and driven as a daily driver for many years by my late great grandfather and now me. After a good bath it has also hauled many of my friends and our stuff down to the river in the summers and gone fishing countless times. Still it has held up and always been there when I needed it. I hope to be able to round up enough cash to do a good restoration on it some day soon with a brand new crate motor and a tougher transmission, maybe even some new gears in the rear. But all in all that is the short story of one GMC truck that rolled off of a Detroit assembly line in 1986...not bad for a truck that started out it's life as an orchard truck. ^_^

limeimac97776 · January 31, 2011

My 1984 High Sierra I got for $1500 had a TH350 transmission and a 350 motor with a quadrajet carb from a 70s truck because the dipstick is on the driver's side. No idea how many miles are on her because the Odometer does not have the 100,000 digit and nobody kept maintenance records for it. It originally had a 305 and a TH350 with lock up. The casing was cracked on the TH350 that was in it so i bought an older (70s) TH350 on craigslist without lock up that im using now. I am eventually going to put a 700R4 and limited-slip gears in my truck.