I was planning the same thing. Towing a boat and a heavy truck camper. I went with a Jakes Stage 2 kit and they let me down big time. Maybe these problem were just my experience with Jakes but a google search for Jakes Performance or Jakeshoe and add reviews and complaints will show you I am not alone in my complaints.
I read through your story. I too went with Jake’s Performance and their Stage 2 kit. I wasn’t completely ignorant of what I was getting into by going with them. I’d read pretty much every post on the forums I could find. I was rebuilding a ‘00 4L80e so I got mostly all the correct parts. They did send the wrong sprag also but corrected the error pretty quickly and professionally for me. They were also kind enough to send me a few extra check balls that I lost somewhere in my garage during the disassembly process. I can put myself in their shoes and can see how frustrating and time consuming it is to deal with novices. I watched every YouTube video I could find and had two paper repair manuals I was referencing the whole time. I tried to do as much as I could on my own and only planned on calling Jake’s if I was desperate. Thankfully, I think I was successful (only 500mi so far). But you’re 100% right, if you don’t have the time or margin to support selling kits to amateurs state that up front or establish some kind of hourly rate for tech support.
If I ever do another one, I’ll also likely just get the parts independently as you suggested. In the end, the only modifications I made were the dual feed and slightly opened up the feed orifices. Oh, I did use the thrust bearing on the output shaft also, but it probably wasn’t necessary as it’s a 4WD tranny.
Link to my build thread with tranny mods details.
Andy’s 1995 CCLB 7.4L TBI to Vortec Swap
https://r.tapatalk.com/shareLink?sh...B-7.4L-TBI-to-Vortec-Swap.45295/&share_type=t