Help decoding big truck vin and engine code
 

I have what I believe is a 1960 Chevy school bus. Trying to find out what the original engine was because it's missing and would like to find a replacement the same size. Any help would be appreciated. Thanks

Serial: 0S5302616139D
Engine : M516922

This is on the tag on the firewall

Re: Help decoding big truck vin and engine code
 

Believe in 1960 6000 series trucks/buses could get a 261 cu inch inline loadmaster engine or a 348 cu inch v8 workmaster engine.

Re: Help decoding big truck vin and engine code
 

In 1960 they also have a 283 listed so it's 261, 283 for the S60 series, it jumped to a 348 on the S70 series bus.

Re: Help decoding big truck vin and engine code
 

Thanks for the info. Just wondering how you decided it's 6000 series? How many ton is that? Is this determined by the S5302?

Re: Help decoding big truck vin and engine code
 

I am using a "Motors Truck Repair " manual as a reference, 17th edison. In 1960 they list the motors for school buses, series S50-S70 the smallest motor is a S50 series with a 235, the rest have either a 261 or 283.
Maybe the motor mount position will let you have an idea of what was in there 6 or V8.

Your S503 could indicate a 50 series. Seating capacity could be a factor for bigger motors.
I have a 60-66 Chevy/GMC assembly manual and it has the vin information, but in your case I just could not find the vin info that matched.

Re: Help decoding big truck vin and engine code
 

This is a GMC specific forum. With GMC enthusiasts and an expert knowledge base. You will be better served to go to a Chevy forum like Stovebolt.com