I Give Up - Why an A-904 Rolls A Sprag?

nm9
I had a situation with a C-4 once too. As to automatics, I normally stick to Mopars and old TH350/400s (cuz they're easy),but many years ago my broke neighbor talked me into rebuilding the tired old tranny in his Ford Ltd.
Well, when I was done it worked great; except there was no engine-braking in Drive.Take your foot of the gas and it might as well have been in Neutral. After RnR-ing the tranny again and the VB separately,as well, and spending a lot of time head-scratching, I came to the conclusion that I had no clue what to do. I did what I believed was the right thing to do. I gave him all his labor money back. He drove that car,in that condition, as a DD for many years, until the engine was really,really,really tired.He replaced it with a Plymouth.
I told myself no C4s ever again.