727 missing spring
yea i thought it was odd both transmissions didn't have one .... i am not sure the valve body is stock or not i been debating if i should by one or not ... i also didn't want it to destroy anything by not having it... would this be something someone would do to with a stock valve body ? Cheap way to make the shifts harder ? i could put a rod in there but wouldn't that make it shift harder ?
Yes, leaving out the spring is what some try with a stock valve body to firm shifts, and it is essentially free if one is already into the transmission. Results vary whether it does firm up the shift or not.
I'm not a fan of the blocker rod, although its use can increase the firmness, and harshness, but it also increases loading on other components, so if it is used, it should probably only be used as part of a system of components intended with its use. A billet accumulator piston is a wise idea. Harshness is not necessarily firmness though...but Mr. Gil Younger could have explained that far better than me.
I'm not a transmission builder, but I've rebuilt 30-40 Torqueflites over the years and I've used a blocker rod twice. Once for a friend's transmission in a 383 Road Runner in the 80s. It was built with all B&M Transkit, etc, and used the blocker rod. Overall it worked well, but it was a complete package. The other is in my 360 Ramcharger using a mix of stock parts, Chrysler cast iron band, Raybestos frictions/steels, old style Trans-Go TF-2 (the one with all the replacement valves), front clutch aftermarket 15 spring kit, deep pan, and some other tweaks. It performs great, but the 1-2 upshift is overly harsh.