Just picked up. Original Paint Original Engine 23k miles. Long Bed Big window trying to identify trans and currently searching out generator and radiator. Engine turns, going to try to get her running before i do anything drastic. Have a built 350 ready to roll but id like to keep it original drivetrain if possible. IMG_1808 by jlanesey posted Nov 27, 2017 at 6:51 PM IMG_1810 by jlanesey posted Nov 27, 2017 at 6:51 PM IMG_1817 by jlanesey posted Nov 27, 2017 at 6:51 PM
It's only original once. This is a great find. V8 logo so Pontiac 287. Is the trans stick or aoto? 3 or 4 speed?
It’s the original Pontiac 287 (gmc 288). It’s a manual trans on the floor. Doesn’t look like the 3 speed I’ve found pics of though.
I see a 'V' on the front fender.....should be a Pontiac 287 cu in V8. If automatic, it is a Dual Range Hydramatic. If a stick shift, is it 3 on the tree or a floor mounted 4 speed? Cool truck, in any case. Ray
If it's an automatic, it has 4 forward speeds (at least my Olds did). First is super low and short. 4th is not overdrive. They are indestructible.
that sure looks like the SM420 granny low four speed trans. They work ok when they're in good condition, but it's not a racing transmission, unless you're into rock crawling.
Truck came from Oregon, stamped date on license plate is 56’ I thought that was pretty cool. The seat needs upholstery and the back gl*** is gone but besides that it’s pretty clean. Gas tank I’d say was perfect condition. All electrical besides generator and condenser are there. I oiled the plug holes and read full at the dipstick so I gave her a turn and it felt good and like it has compression.
I found this online after purchase while researching. It’s actually my truck. http://www.originalpaintcars.com/dripping-with-character-1955-gmc-100/#comments
This might make sense, it looks like it was outfitted with heavy duty options, like the 8’ bed, steel hitch bumper, V8 etc. The script on the door is from a gl*** company so maybe a delivery truck? Only 23k so it hasn’t gone too far.
here's a picture of the whole transmission, which I found by googling the casting number on the case in your picture. You could do that, too and I'd be shocked if that's the original mileage. if you can post more pics of various parts of the truck, especially those parts that get wear, we might be able to hazard a guess whether it's 23k, 123k, 223k, etc. Old trucks usually got a LOT of miles on them
Ive got one of those 55 GMC,s in my hoard. Mine is a short bed, 287 with a Muncie 318 three on the tree trans. Any Pontiac V8 from 55 thru 59 will bolt on your GMC. I always thought a 59 389 would be the berries.
Thanks you found it. That’s the one, I like the heavy duty trans. I live where there is more hills than straight always. Northwest Connecticut. That’s a good point about the miles. Maybe she rolled over a few times. What would be best places to look? Engine bay fender walls are almost glossy when I wiped them down very clean. Interior besides the seat being destroyed from lack of back window still has original covering. There was some heavy grease buildup on front motor mount but again it’s 60+ years old. I’m doing some research now on “Selby Gl*** co.” In Oregon. Maybe that will give me some clues. That one page says it was in storage for quite awhile and was ***led to original owner.
I think a 60 389 will also fit. Dont know if it would still have the reverse cooling. Ive been collecting stuff for my GMC, got a tri power. And its very rusty so I collected a couple of solid chevy cabs. haven't decided if I will patch the GMC cab. Or just install the GMC dash in a chevy cab? The OP's truck looks like a really clean solid project.
I’ll take some more pics tommorrow, I’m in the middle of ***embling my 54’ Cj3b so I can shift it into the garage before snow hits here. My CJ that has lived its whole life here has been patched more times than I can count in its history and the frame has definitely lost some thickness in spots. After that experience I’m excited about the General solidity of this truck. All the mechanicals really look to be in halfway decent shape, leaf packs etc. frame is rust colored but not a single bit of flake on it. The only rot I could find is directly below drivers feet but it is really only about a 6 sq inch area that is bad. I did some more research and found who likely owned the truck. Just wish I could find out who the eBay seller was that my guy bought it from. Looked up the posting but deleted because of the age.
I pulled the gas tank and seat today to vacuum the broken gl*** out, there was a receipt in the glove box for condenser and points from 1962 in glove box for something like four dollars. Also pulled out the factory floor mats that had very little wear but we’re all dry cracked and rotted and the sound deadening so I could look for rot.
I'm jealous! A 55-56 GMC is second from the top of my "bucket list". I've had a bunch [11] 55-57 Pontiacs and I've used '59 and '60, 389s in several of them. The 59 engine is still reverse flow and the 60 isn't but it really doesn't matter. They're both great engines with no cooling problems. Lotsa low end torque. You'd be buying back tires regularly. Congrats!
My 5 year old son really likes this one, this day of looking at it with him and his joy in it is what made me realize I had to have it. This pic is from a year ago. Finally made it happen. Excited to share this hobby with him. Sent from my iPhone using Tapatalk
For what I can see, and with the 1962 receipt, and old plates still around, I would tend to think it is low mileage.
I saved the receipt I’ll up a picture of it tommorrow. Also found what looked like a folded up shirt but the only thing distinguishing was the ****ons. And a very old brochure for some kind of well pump. Sent from my iPhone using Tapatalk
Cool truck. I like it a lot. Your gonna love it. I've got a 1957 GMC long bed, big back window. I've had the truck for about 4 years now & my son & daughter love it. As a matter of fact my wife actually likes it too. Ha ha. I think it's grown on her & become part of the family. Mine has a 350 Chevy in it, but I purchased a 347 Pontiac motor & trans a couple years ago that I intend to rebuild & put in it as I like to keep them somewhat original. Here's a couple pics of mine. Sent from my iPhone using The H.A.M.B. mobile app
Bad ***, I like how the chrome is a little less congested on your 57’, I have a built 350 that I’ve been holding onto for awhile and I thought this might be the one, if it truly low miles though and the engine internals are good I’m going to leave it as is. I was amazed when I pulled the stick and it had oil in it, it actually didn’t even look black. I gave the engine a little turn at the crank and it was smooth in the mid stroke and definitely making compression. Any thoughts on cleaning the heads? When I pulled the valve covers it was like a sheet of sludge fell down. I never had a project without an engine that I already knew definitely needed to go to the machine shop so I’m a little troubled on where to start with it.
If the sludge is dried, then a vacuum cleaner might do the job. Pics? Usually takes a lot of miles to get a lot of sludge, though.
I beg to differ with squirrel on the sludge. High mileage isn't necessary for sludge to form. If a vehicle is only run for short trips and never really gets up to operating temp it can very quickly sludge up. and the oil back in the fifties wasn't all that great. And the lack of a PCV also contributes to sludge formation. What I suggest is you pull the oil pan valve covers' intake manifold and valley cover and spray it down with engine cleaner. and wash it out with a pressure washer. Or just hook up a garden hose to your hot water heater. immediately after washing it blow it dry with compressed air. The truck originally has a canister oil filter. You can obtain the aluminum oil filter adapter from any newer Pontiac V8 and convert to a spin on oil filter. really soak the cylinders with a lubricant. I like to use a mixture of 50% diesel and50% auto trans fluid. Put a kit in the carb. and using a small gas tank gravity feed the carb when you first try to start it. The fuel I prefer to use when waking up a zombie has 1/2 pint of 2 cycle mixing oil added to each gallon of gas. And the newer Pontiac HEI will fit the 55 engine. also I would hook up a PCV. I found a rubber grommet that fit in one of the valve covers to install a PCV on my 55. There isn't a lot of wear on your pedals. but the pads can be changed. Look for wear in the clutch linkage and spring hangers. Its possible you indeed have a low mile truck.I would keep a Pontiac mill. There is a Guy on U tube Jeff Bradshaw goes by Elderly Iron. He is a GMC guru. His videos are very informing.
lots of times a engine that has been setting a long time the oil will appear really clean. That's because all the heavy deposits have settled to the bottom. and the clean thin oil rises to the top. A good oil gets black very quickly because it holds deposits in suspension. A non detergent oil don't get black as quickly.
Without seeing the sludge, it's pretty hard to tell how many miles are on the engine....could be low mileage, but it's not likely.
One shure way to tell if its low mileage. Pull the heads if the cyls do not have any ridge its low miles. I once bought a 64 galaxie with only 16,000 actual miles from the original owner. She lived in greenbriar ark. And only drove it a block to work at the post office. And after a half dozen years she retired and parked the car. And the engine and transmission where both shot. I got it running and the head gasket blew between the block and cyl head. compression was excaping sounded like the spark plug wasn't in it the gasket was rusted away. It had a 289 & C4 automatic. That 5 bolt 64 bellhousing is a very rare item. I sold that bell to a Hamb member a few years ago.
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