Ok fixing this 15 year issue and a 727 question

Yeah when I was in High School in 78-79 I had a 2 hr auto class and we needed a project car. I bought a 71 demon with a slipping 727. Week 2 my instructor helped me rebuild it. I ended up rebuilding 11 more that year for others and EVERY single one had a bad seal on the 1st/reverse clutch. I think after all the years and engine swaps, those linkages for the throttle pressure/kick down got tossed and I swear that is the issue with most of these now, mine included. The Lokar cable is just not the same in my opinion and I'm still fighting mine on my car to get it right.