The Stovebolt Site Forums The Parking Lot Big Bolts GMC model id

I have an opportunity to acquire a '53 Jimmy, its a big one. The title says its a 1.5 ton. However, I suspect that info is incorrect. The truck has Dayton style wheels on it. The VIN on the title is A270815245. I have not matched it with the id tag in the door jamb yet so I do not know if in fact that number is the VIN or the s/n off of the chassis. The title is from 1973 in Texas. I know many states used different numbers to id vehicles. I just want to know if its a 1.5 ton, 2 ton or 2.5 ton or larger. Title says it weighs 8600lbs. I know my 1950 chevrolet 4100 MIGHT weigh 5k, but nowhere near 8600. Weights on Texas titles are supposed to be curb weights, not GVW. I have sesrched this topic all evening and just cannot find any obvious answers. Any help will be much appreciated, thanks.

Engine SN and location would help. Engine SN up to 302's is stamped on pad behind distributor, r side. 360-503 is l side aft end of crankcase, stamped, hard to find-dark in there, back by firewall.

Tire size also help. Picture?

Ed

Hy mechanic58, the number you posted looks like an engine serial number to me. Maybe that is how Texas registered vehicles in those days

A270815245
A = a variance from standard specs for cylinder bore and/or bearing grinds/specs
270 = 270 ci GMC engine
815255 = sequence/serial number

Specific details on coding are shown on RobEnglish's oldgmctrucks.com website.

As posted by 3B, many GM vehicles were titled by using that engine serial number for vehicle registration (ID) code. (For some inexplicable reason).

First thing is if you have a VIN tag/Serial plate on door jamb you are lucky. That is the number that should describe your truck. Post that number. So far it seems you have a 250-24 1 Ton. Should have a 248 Cu in motor unless replaced or "special order". There is a GMC FC 253/263 possibly. Not sure.

1 Ton is shown as GVW 8800. Maybe someone misread/mis stamped something. Again not sure. Need VIN from door jamb. Titles are frequently misleading in those eras. Especially GMC.

Check for emblems of any kind. Check stampings/casting number on motor.
People in the know will go by lug pattern, wheel size, axle size, spring size and other physical features to identify. So a couple of pics and some specs won't hurt. Duals? Stake? Dump? Flatbed? Wheel base?

The s/n on the ID tag in the door jamb is 402 27 1679. The GVW rating is 17,500lbs. The combo gross is 30,000lbs. Pretty sure its not a 1.5 ton. The number on the title appears to be the s/n off the engine. Has 9 or 10.00 x 20" rubber on it with dayton wheels. HUGE 2-speed axle with "GMC" embossed in the rear cover.

I own it now btw, just don't have possesion of it. Will post pics later on. I'll have to make another trip to collect it. The previous own needs to 'un-bury' it and extract it from its current resting place so I can get to it to load it on a trailer. I did view it in person today. It had a dump bed on it originally. Now its just a cab and chassis, however I believe the pto and the hydraulics are still present.

The GVW minus the curb weight listed on the title works out to 4.5 tons.

400 series is 2 1/2 T. 402-27 149" WB. 270 Motor. Big MoFo. 18,000 GVW, 30,000 GCW. 15,000 Rear axle, 4500 front axle.
Looks like the motor number was used instead of the Serial as many MVD's did. Was not a good idea because motors got switched out. Your motor is probably original. Allegedly the block casting number can identify the era, the head casting no. can identify the year. Could be date codes also. Not sure about GMC.

400 series 2 1/2 ton is a Rare truck. You don't run across them as much as you do the 450, or 470 series trucks, which are rare in themselves. Great find. Rob English (www.oldgmctrucks.com) has one. Check the back of the glove box lid for all the trucks vitals. It's not a 4 1/2 ton. My '52 470 series GMC COE is a 3 1/2 ton.

Texas used the engine number for titling until the mid 50's. I have GMC trucks titled by engine number up to 1954. I have some 55 Fords titled by chassis number so it seems like that may have been when Texas made the switch. If you don't have the original engine, there is nothing wrong with changing the engine number to match the title. In fact, I would recommend changing it to match the title because Texas has no provision for altering titles. Altering a 17 digit vin number is illegal. Texas law does not address chassis numbers before the 17 digit vin with the 10th digit indicating the year model became the national standard.

How do you change and engine number? It's cast or stamped.

Thanks for the information guys. I knew it was rare. I had the pick between two - the other truck was a '57 Chevrolet 6400 with a late model sbc in it and a full complement of widowmakers. I think I made the right choice. I am probably just going to get it tidy'd up and get it running and sell it. I got it in a trade deal. I already have a much better '50 4100 Chevrolet that I am concentrating on. I just
wanted to rescue this old Jimmy.

GMC had a flat boss at the distributor with stamped numbers in those days. When you bought a new short block from GMC, it had the first 3 which was the displacement such as 270, 302 already stamped and the installer stamped the rest to match the title. When you installed a used engine, you simply ground the boss down and stamped numbers to match your title.