ok i have been searching and i couldnt find the part number for a comptech novi 1000 running a 3.8" pulley. i see in the faq that

4060390 4.0inch(7#)
4060385 3.5 3.35inch

so does that mean i need the belt for the 4" and also is that a gator back belt part number?

 

That should be a Gatorback belt number. I don't know for sure, but you should be fine with the 4" belt, the 4060390.

If the 4060385 (which is 38.5") works with both the 3.5 and 3.35, then the 4060390 (which is 39") should work with both the 4" and 3.8".