450c or d?

[Rincon]

What is
A major difference between a 450c and d? No serial numbers any where other than the engine. The oriGinal under carriage I assume is at 50% based on my owners manual. Have had the dozer now for 3 years. Replaced rebuilt a final drive three years ago after I bought it. And last year I rebuilt the cylinder for blade 6 way. Runs awesome. I'm assuming it is a C. There has to be another way besides serial number. No rivet holes, nothing.

[B Town]

D series has level /flat floorboards. Front and hood are square.

[Rincon]

Awesome thanks. I was certain I have a late model C.