I've got a 85 C10 Silverado that is very solid mechanically and cosmetically, but my problem is the 700R tranny. I have spent a fortune over the last 22 years in tranny repairs so now I am considering an change-over to a Muncie M21 or M22, or perhaps a Borg Warner T-10. Have any of you done a project like this one? If you have, please give me an idea of what I am looking at on parts availability, etc. My truck is a ranch truck, so the 4 speed would work great for the job that the truck does. Thanks for your help!