Hy Mathew Blair, I believe the serial number plate in your picture came from a 1955 second series GMC 350 series with a 154" wheelbase, originally equipped with a 316 c.i.d. Pontiac V8 engine. Obviously these specifications do not match what you have now, the engine you have did not come out until the mid sixties and the serial number plate is from a single axle truck not a tandem. If you provided pictures of the whole truck we may be able to find some clues as to what components make up what you have there, hope that helps.
A 1955 makes sense. I have attached the most relevant pictures. As you can see it does have tandem duals. If you look carefully at the picture from the rear it shows a differential on the rear axle, so I’m not sure if it’s a twinscrew or not. Also on the side of the hood are Chevrolet Spartan badges right next to the GMC emblem. In the engine picture it shows 366 on the valve cover. Do I have Frankenstein‘s monster? Before I drive seven hours to go look at it I would like to know something about it more than is evident from the pictures
Matt
"Brunhilde II" '59 Viking 60 To paraphrase Ben Franklin: "Big Bolts are proof that God loves us and wants us to be happy"
Hy Mathew Blair, the picture from the rear is too dark to make much out, but I don't think the chassis is a 55 - 59 Chev/GMC tandem. The rear axle housings on the 55 - 59 tandems were flat on the top and bottom. I think you are truly looking at a Frankentruck there, let us know the results.
The steer axle axle looks like ti came out of a 400 series. Is it a full tandem or a drag axle. If it is a full tandem, it came out of a larger truck like a 400 or possibly a 500 series. It was common to make a bigger truck out of a smaller one in those days. The cab and the hood are right for a 350 so the chassis and the title probably match.
Look for a splice in the frame rails ahead of the drive axles. A twin screw will have differentials on both axles and a short driveshaft between them. You've probably got a dead "pusher" axle ahead of the rear one with the drive gears. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Bigger tires on the front rear axle indicate the rear axle is dead(tag) axle. Common trick in the day to run larger tire on the drive because of no suspension movement.
That truck was assembled from other parts, But a nice old horse non the less. Tom
Your engine is likely a 366 big block Chevy. This was a "truck only" displacement of the 366, 396, 402, 427, 454 CID big block series which was used in passenger and truck applications from 1965 through sometime in the 80s.
Unless you've "just got to have it", so much has been changed on that one, i'd stay away from it, if it was me, and look for something more original. jmo.
Spanky Hardy Collector Of Fine Old G.M. COE Trucks & Antique Holmes Wreckers