Most of the C's came with the semi U blade which is much better than the straight blade. The B's had a shorter track and was not balanced as well as the C's.

Around 78 they started using the inline injection pump which is better than the rotary that ours has (same style as 1066 ). Ours might have been a B, it didn't have the 466. We have had a 15C for 20 years, like any dozer, they are expensive to maintain, but much cheaper than a Cat. Parts are much more available for the C's and they made alot of improvements to them. The B's had the same engine as the IH 806 tractor. In dozers it's easier to repower, only have to match bell. Internationl boys can tell what motors swap out with bell housing. Bottom line was one of the best dozers we ever had, fuel economy was good. That TD15 would sure push more than a 450. Most newer dozers have a 3 or four speed power shift. Most of our operators used the low range, but I liked the high range, pushed most of dirt in low, backed up fast in 4th. In high range, the low is 2nd and high is 4th. For you pushing and backfilling loose dirt behind excavator, the high range works great. Worked perfect, push out tree, shift to high (3rd ) move dirt or tree and then had the fast reverse. In the low range (used 90% of the time, ) the power shift was first and 3rd. Had a High-low range selector that had to shifted manually, dead stop. Had a torque convertor, with 2 speed power shift. But if I had a cab I am sure that it would get a lot more use. Mostly leveling dirt behind the excavator. What does it weigh compared to the D7? How does it shift, is it a power shift? What engine did they have and was it the same as an ag tractor? I think that the later ones had a DT466. I would just like to have a cab (kind of a wimp on a windy November day ) and a little newer machine. I currently have 3T D7 cable dozer for the last 25 years so remember I am pretty easy to please.

Parts list for a td 15b dozer