So I would like to firm my shifting up as much as I safely can. Whether it be TP Valve Bodies or the J-Mod I am undecided. The J-Mod is much cheaper, but many people say that it is less useful on the newer trucks. So can some experts chime in and tell me what I will be happier with?

I plan on going supercharged down the line, but thats not for a long time to come, so I think I am just going to eat up the stock tranny when I do it.

 

I've got an '04 with the 4R75W. I'm rebuilding it now and wanted to put a shift kit in it. After discussions with some tranny guru's on the board, the late model trans already have larger fluid paths, so the jmod doesn't do anything. When I asked about a shift kit / plate, I was told again that the holes in the plate are actually smaller than the ones that I have already, which would hinder fluid flow.

For firmer shifts, I've been advised on swapping and replacing some springs in my accumulators. This is what I'll be doing along with a complete rebuild, new clutches, steels, od band, EPC solenoid, etc.

 

What springs and where?