I have a 1950 4100 with 2400 original miles on it, and need to buy 6 new tires. 3 of the rears appear to be original US Royals in a 6.50-20, and the fronts are some maybe 30 year old Co-Op 7.00-20. I cant's decide whether to stay with that setup, or just make all 6 tires 7.00-20's? The staggered setup I have works okay, and look right. I like the 7.00-20 on the front, but a bigger rear might not? Also looking for a place in easy driving distance to pick up tires near NE Iowa, and maybe get mounted? I wish there was a better modern setup all together for these old trucks, but there are no great options, and it looks like it will be $2000 plus no matter what.
Last edited by 4100 Fire Truck; 04/03/201911:23 PM.
Lots of time you cant put wider tires on the rear of those trucks as the can rub against each other. When new they had the same size front & rear. George
Last edited by Wrenchbender Ret.; 04/04/20191:33 AM.
They say money can't buy happiness. It can buy old Chevy trucks though. Same thing. 1972 Chevy c10 Cheyenne Super In the Gallery Forum
Actually when new they always had larger size tires on the rear. I know this is true for the 47-54 models. Example, if it had 7.50/20, on the front, it would have 8.25/20, on the rear. If i were you, I'd run 7.50 front, and 8.25, on the rear, if you have the clearance. The larger tire size will help your rpms.
Spanky Hardy Collector Of Fine Old G.M. COE Trucks & Antique Holmes Wreckers
Just my two cents, I would run the largest you can with all 6 being the same, you have a lot more options when it comes to tire rotation and also if a tire is damaged beyond repair you have a spare already on the truck without having to worry about which position you are going to try to match. My experience is from owning three Chevrolet dual wheel pickups over the last 40 years and with my '57 5700.
Last edited by 78buckshot; 04/04/20199:36 AM.
1957 Chevrolet 5700 LCF 283 SM420 2 speed rear, 1955 IH 300U T/A, 1978 Corvette 350 auto, 1978 Yamaha DT175, 1999 Harley Davidson Softail Fat Boy
I think I am going to try the Samson tire in a 7.00-R20. It is a radial, with 14 ply and probably heavier duty than what I need. I like the idea of radials though, but have no clue how they will do? Looks like a good tire for $190 ea. 6 tires, with flaps, and tubes delivered for $1250. I plan to order them on Monday, unless I hear a reason not to?
Last edited by 4100 Fire Truck; 04/05/201911:48 PM.
Since you have the GM 5/10 wheel bolt pattern, the first tubeless tires were put on tubeless rims with that bolt pattern. Many were put on farm trucks in the late '50's. It might be worth looking around for some of those tubeless rims, even if you can find a pair to start with.
Ed
'37 GMC T-18 w/ DD 4-53T, RTO-610, 6231 aux., '95 GMC running gear, full disc brakes, power steering, 22.5 wheels and tires. '47 GMC 1 ton w/ 302, NP-540, 4wd, full width Blazer front axle. '54 GMC 630 w/ 503 gasser, 5 speed, ex fire truck, shortened WB 4', install 8' bed. '55 GMC 370 w/270, 420 4 speed, grain, dump bed truck from ND. Works OK.
