1977 GMC Sierra k25 Overview and a Quick Update

[@fcarp1685]

Awesome truck. Glad to hear it will be parked in the winter that is a survivor.

[@5Tractorguy]

Thanks Alex, without a doubt!

[@regsparkes6507]

You are very lucky to have found that model/year truck with little to no rust. That year/era of GM trucks were infamous for rusting chassis ( right behind the cab ) and rusting rear cab corners too, to name two. It is a nice truck, especially for that 4-speed trans.

[@5Tractorguy]

Thanks Reg. Rusting cab corners and rockers for sure. Someone did do those on this truck, not the best job, but it is solid again. Either way I can't complain after everything else I saw while searching.

[@straightpipec6099]

Awesome truck. Good to see a new video. The radio is definitely after market. My dad put one in a 74 Chevy van to play 8-track tapes, many years ago. Lastly, oil spray does work despite what you might see on the internet.

[@5Tractorguy]

Thanks C60. I had a feeling it was, if I can get the antenna to work or ad an external one I'll keep it. That's what everyone tells me! I think I may continue to do the same before this gets parked for the winter. Hate to see it start to go now...

[@johnchaffin5494]

Owned many a Chevy and GMC because they are great vehicles. I have hung on to my 1990 Chevy 3500 with 454, it sat for ten years broken down and put a new battery and found the problem (distributor) and fixed it. Fired right up and still using it 150,000 miles on it.

[@5Tractorguy]

Good year Chevy! I still like the 88-90 body style and interior. After that, my interest drops right off with GM trucks.

[@RooneysSears01]

Man that brings back memories, my 3 brothers and I all had one of these in the late 80's early 90's same thing they ran great but just rotted away. You got a true survivor Jake and she's in excellent hands now.

[@5Tractorguy]

Thanks Rooney! Seems like these things were everywhere back then from the sounds of it. I suppose if you have a good thing going....

[@1997cr80r]

I just got a 85 custom delux 30. Also has the big heavy duty west coast mirrors, granny 3 speed, dually, flat bed. It was a fertilizer truck no never driven in the winter. Has 50k miles originally a 6.2 diesel but now it has a new gm goodwrench 6.5 diesel non turbo. It's in really good shape. Them aintenas in the windshield pick anything up

[@5Tractorguy]

Good deal! I almost bought another 1-Ton instead of the pickup but figured this would be nice for a change. Sometimes you get lucky and people take care of them over the years. My antenna should but the windshield cracked some time ago just above the plug-in. Not sure if it nipped the wires too.

[@jeremyjencks5864]

Nice truck wish I still had an old square body yet

[@5Tractorguy]

Thanks Jeremy

[@benhowe5506]

I love the new project truck, i like the way it looks now. Nice low miles too. Great find brother. Keep up the great work.

[@deanbarr5740]

Great find. I used to have a '86 that i bought new. Wished i still owned, i let my nephew have it. They are good trucks.

[@5Tractorguy]

That must've been nice! I would have loved to own one of these trucks when they were new. Heck, you could still buy a real work truck back then for a reasonable price. Now new ones cost more than what most normal people make in a year...

[@thedriver02]

Nice find. That truck is a gem!

[@michaelcook768]

Even down in VA, those trucks became rustbuckets. I way prefer the design than the newer ones. A 1978-1982 Silverado was a beautiful truck...same for the GMC. A 400 small block was great in these trucks.

[@5Tractorguy]

You said it! Much rather be driving one of these. If you think of it... my friend has an '05, the 6.0L, gets about 11-12mpg, same as what my '77 gets. For all I'm concerned the '77 has more style and integrity that than '05 will ever have.

[@michaelcook768]

5Tractorguy I agree 100%

[@drjohnsonhungwell5115]

Love the square bodies I have two of them a 78 swb 350 sm465 205 and 4.10s and an 86 military blazer with the 6.2 Diesel TH400 203 and 3.08s

[@jingorat]

sweet rig. Hard to find these trucks nowadays. That's why I cherish all of mine. Looks like the 465 has the typical shifter slop from broken shifter ball welds too haha cheers buddy

[@tedlachcik2607]

Nice old truck I would definitely cruise it

[@drjohnsonhungwell5115]

The rattling sound you here when shifting gears is the transfer case shifter mine does the same thing you can touch it and it'll stop I'm going to get the new boat that goes through it with the bushing for mine.

[@Searsnut11]

Nice lookin rig! Looks even better then it did in the previous pictures! Im glad its workin out for ya. Ill show my buddy the cam spec sheet and see what he says, he is a bit more knowledgable about them then i am.

[@5Tractorguy]

Looks a bit better now that the dang plow is gone! Definitely, if he conjures up something give me a shout...

[@stevemino142]

Awesome truck...however I've never heard of a turbo 400 trans slipping or needing more than one overhaul in a lifetime on your 88 had an 87 service body 1 ton with an early TBI 350 it too had a problem with the TBI unit but the truck had 350000 km on it when i got it but it was a simple fix 50 dollars Canadian at a swap meet got a low mileage reman TBI unit the overhaul kit was 250 lol apparently the early units were prone to flooding in the cold until about 1993 when they changed the way fuel swirls going in thanks for uploading good video

[@cattmann1405]

That frame looks amazing!...another 200K left on that one. Have to try the oil spray on the next truck...too late for my '95 f150. Used to work at a landfill..the owner salted the crap out of the access roads...ate my '88 F150 alive!! You've also got the built-in theft deterrent....manual tranny.. Gotta put your logo on the door panels...aged to match the truck.

[@5Tractorguy]

You bet it does! And that's why it's taking a break when the winter comes. I wash my '88 1-ton a couple times over the course of the winter but it still gets a bit worse every year from the liquid calcium. That would look cool! It would be neat if I could find someone to hand paint it and then clear it. Bet it would cost a few though...

[@cattmann1405]

What would probably work, Jake, would be to project the image to a white board type surface. Cover the image with frisket film...cut out the negative, then apply the negative to the door. Then air brush or rattle can the image..then clear coat after removing the film. Little time spent but not a bunch of money...rainy day to do list.

[@rustyoldjunk]

Hello. A while ago you worked on a Lincoln 225 welder, and you had an extra motor. I was wondering if you would sell the governor shaft and arm out of the spare motor?

[@jasonmushersee]

i knew a tractor mechanic that had one of these. 350 with headers 4 speed manual he took it to truck pulls everywhere all through the 80's and always got a full pull. this out pulled ford 3/4 tons with 390 in that weight class. i drove a 79 silverado big10 for 9 years. dependable but rotted out

[@5Tractorguy]

With a stock drive train? That's pretty impressive.... I always had half a mind to do that around here at the fairs and out pull all those dang "bro" trucks. That figures, my '88 is the same way. After 7yrs on the road the salt if starting to get to it.

[@LouCFur90]

Nice rig 👌🏻

[@workingcountry1776]

Nice truck! Im looking forward to picking up my 86 k20... mine has the 8600# GVW so that will be geat for my lawn care business. Only down side to my truck is it has a th400. I would much rather 4spd granny low with such low factory hp

[@5Tractorguy]

Thanks! I found a couple 80's K20 online before I came across this one, love to find a K30 single wheel from that era... Good luck with it. Can't beat the 4spd, but after a long day of work it's nice not to have to shift!

[@workingcountry1776]

@@5Tractorguy I've been driving my k20 the past couple days. It can't go highway speed but it runs geat...

[@kbtruck65blair64]

Nice truck

[@truckandtractorgarage740]

Its great to see you're back at making videos! That is a really nice truck!!!how many rpms does it turn at 60?

[@5Tractorguy]

Thanks Donald, yeah, been a while!! Runs about 2800+/- at 60. I have a 300+ mile trip planned with it end of this month so we'll see how it does.

[@lewiemcneely9143]

That is a SWEET BABY! Don't worry about the videos. Got to make the bolts fly before the snow does. I put a set of Craftsman deck wheels on the kidney mower and no more scalping. Anything can be improved on. Keep after it pal and 10/4 on the bluegrass and GBWYall!

[@5Tractorguy]

You bet Lewie! Good stuff on the deck too, little but if ingenuity goes a long way!

[@zanehokanson1318]

that third gear sinc like to yell at ya

[@lewiemcneely9143]

Keeps you honest!

[@terryraymond7984]

Does that only get around 10 MPG though

[@ronaldziehlke9720]

Wow, no road cancer!

[@ayp1938]

do a video on the 88 1 ton

[@auburnfolsom]

Looks like a pretty nice rust free truck that was well cared for body / frame wise. Should be a nice ride for you. Those square bodies ('73 - '87 [the '79's had bad metal because of a steel strike I seem to remember]) were bad about rusting out at the tops of the wheel openings on the fenders in snow / road salt country, as I'm sure you know. I'm not wild about standard transmissions & aluminum chain driven transfer cases found in most of them. I prefer the gear driven NP 205 (like I'm sure your 1-ton has). Also it can get very tiring stirring the soup of shifting gears in stop & go driving / in heavy traffic. Not to mention getting a bad case of clutch leg. I'll take a good Turbo 400 any day, but that's me & I'm old. The key with the Turbo 400 is to find someone who is Familiar & Competent at rebuilding it & knows the upgrades that can be done. Also not to abuse (spell that: try to use it in an application it wasn't intended / designed for) & to keep it full of CLEAN fluid that is changed regularly if used in harsh conditions such as towing, a lot of heavy hauling & snow plowing !!! The TH400 was one of the best automatic transmissions ever made. Far superior to the Turbo 350 & much of what followed with electronics. Just something to keep in mind. Not trying to burst your bubble or criticize your new truck, just some thoughts & observations that I've learned over the years. I have a '72 Chevy K2500 Custom Camper with a carbureted GM Good Wrench 350, a Turbo 400 & NP205 transfer case, dana 44 front & Corporate 14 bolt rear. CA rust free body & AR rust free frame. I converted it from the stock Turbo 350 to Turbo 400 several years ago to make it more reliable / heavy duty transmission wise. Looking forward to your upcoming video's on the WI THD. I just got into playing around with those & the TJD's myself in the past few months. Had never really been a fan of the WI's, as they are so heavy & bulky compared to the cast iron Briggs & Kohlers. I have thus far picked up 2 THD's & 1 TJD. One of the THD's & the TJD has electric start. Can't say (thus far) that I'm a fan of the crank start. I think it could be a wrist or arm breaker, if the engine kicked back. It will be interesting to see what starting type your's has & your thoughts on easy of starting & potential injury possibilities if it's a crank start. Enjoy your video's & your skills. Keep up the good work ! :)

[@5Tractorguy]

So far so good! Really been enjoying driving it. I didn't show it much in the video, but the back of the bed wheel openings were "fixed" at one point with fiberglass resin and paint. They aren't nearly as bad as most NE trucks so it will be and easy fix when the time comes to repaint. Far as I know this has the NP205, it looks identical to the one in my 1-Ton. City traffic when running parts/machines is a pain in the neck (especially with the '61 GMC), I've learned to leave plenty of room and play the lights to avoid shifting all the way up again. I don't mind the TH400's and heard that they are great transmissions, but the one in my '88 must be messed up something awful to be slipping still after 3 rebuilds. It got to the point where I just wanted to be able to get in a reliable truck and go. My 1-Ton was never consistent on the way it ran either, so mileage and power was terrible. Friend of my fathers has a junk '91 with the TBI so I'll be pulling the entire system out of that and swapping into the '88 with one last effort to get it to run right. Found another 4WD TH400 on CL too beginning of this year with a blown reverse. So come September I'll be pulling the transmission again and having the CL trans rebuilt. With any luck this will do it because I would like to continue running that truck, being a 9X8 flat bed it's perfect for hauling equipment and garden tractors. Not a worry, always up to hear others stories with these old trucks! The twin cylinders I like, especially they way they sound! If you go way back in my videos there's a couple THD startups from old Hobart welders that were taken apart. Once my last tractor show is over, next weekend, I may have time to film more. Also have a Cub 782 slated for a video too... too many projects, not enough time! Will do, Thanks!

[@jeremyjencks5864]

Try LMCtruck .com for your grill

[@lewiemcneely9143]

If you got the bucks, they've got the parts!

[@5Tractorguy]

Did, they've got every GMC grill but this one! Go figure....