D2 6J year

I have recently found a 6J D2 tractor that appears to be all original. I want to know what year it is, and if someone knows of books for it. Serial # 295. Also, somewhere maybe there is a older reference book, as far as serial number breaks and such?

Could it be a 3J or 5J designation rather than a 6J??

No, it is a 6J, it is a gas engine.

https://chriscomachinery.com/antique-caterpillar-machinery/

According to the information posted on this site - R2- 1939

That is a neat site. Thanks for sharing. What does the SP stand for? Special Parts? Assuming it has a little higher gearing for farming?

A few places I’d check next: the Antique Caterpillar Machinery Owners Club (ACMOC) (they have members and reference material who specialize in dating early Cats), your local Cat dealer or Caterpillar archival/service department, and dedicated vintage-Cat forums and Facebook groups — folks there often have serial-number break lists and can ID subtle details from photos. Also hunt for the original shop/parts manual for the 6J/D2 series — those manuals (and period parts lists) will help confirm features that changed year-to-year. If you want a hand narrowing it down, post clear photos of the serial plate, engine tag, and overall machine (side/profile slope rider + closeups of decals and unique features) and someone will likely pin the year down quickly. Congrats again — that sounds like a fantastic project!

SP did stand for Special Parts. This was a warning embedded in the S/N to anyone asking for parts from the dealer, and the dealer, that there was factory installed optional equipment that might make that machine a little different. Parts books specific to your model have serial number ranges for not only updates that improved serviceability over the years but also Special Parts .

In the case of my 1936 Twenty Two 2F7403 WSP the W indicated wide gauge and SP was a rear PTO with an engage/disengage lever. You're going to have to do a little research to determine what options SP refers to on your machine.