Ok, I just took apart a 2004 Mustang V6 4R70W and have pulled out the 1-2 accumulator. There was a Green spring on top and TWO springs on the bottom, a Dark Blue Inner springs and a Yellow Outer spring. After looking this up, it seems this is the combination used in 2001-05 4R70W's.
From my reading, I understand that those bottom springs control harshness under part-throttle conditions. On Daniela's car I have a Purple bottom spring which I see was used on 1995-97 4R70W's. Part-throttle shifts on hers is fine, but I don't like the WOT 1-2 shift and wish it was firmer.
So, now I'm getting ready to do my 1995 Mark VIII LSC j-mod, I've got the 2004 valve body and will drill out the plate to the 350-400hp specs. While I've got the tranny out, I'd like to do a few upgrades including mechanical diode, EPC solenoid, and Sonnax Sure Cure (includes pressure regulator valve, PR
boost valve, 2-3 valve endplug, OD servo pin, intermediate clutch snap ring & some PTFE seals).
1) Do I have to replace the whole reverse drum pack to install a mechanical diode?
2) Should I use the XL3P-7G383-AB 5.4L, 5C2Z-7G383-AB or original replacement EPC solenoid (I've read somewhere that later model EPC's don't work correctly with older ECM's)?
3) Can I use the shift solenoids from the 2004 main control?
4) I will keep the Green upper spring, but am considering leaving either ONE of the bottom springs out or BOTH - what would you do?
5) What else should I do since I'm doing these upgrades?
6) Are these different size alignment pins gonna be a problem or can I just bolt this 2004 control to my 1995 case?
Thanks in advance for any and all input!