I am 90% sure it is the cylinder, but I will take a good look today. the entire inside of the bell housing is caked in burnt black goo. As far as the sach's number, the last digit is covered and I cant read it, but it is a round number like 0, 5, or 6. I spent hours calling gmc truck suppliers and clutch specialists and nobody seems to know what I am talking about. I am going to order the part on Spareto and cross my fingers, I have bad luck with international orders, and websites from countries I can't identify on a map. The pic looks the same. and the number says it is a replacement for GM 15002665. I will report back and try and post a pic of what I have, thank you for the help.

I have tried a few parts places, and I can't source a used one.

Also on the spareto website, it has numerous crossover part numbers and one is a john deere part for a tractor, so I might just try it...thanks again.