So I did a t56 Magnum swap a month ago after blowing up my second r154. I have about 1000 miles on it now and I just wanted to share some info I had with you guys and maybe answer some question I had going into it that I couldn't find the answers to.
I bought everything I needed from grannas raceing. The kit came with the Tranny, steel QuickTime bellhousing, cross member, reverse light switch, shifter and all the hardware you need. I also bought a clutch line kit and clutch masters clutch kit which came with pressure plate, clutch disc,throwout bearing/slave cylinder and pilot bearing. He also sold me a billet machined clutch alignment tool for 60 extra bucks and I'm not really sure why because the clutch kit came with a plastic one
I got the clutch masters fx300 disc rated for 600lbs of torque. Trannys rated for 700 ftlbs. It feels good. Slipped until it broke in. Now it's a little chattery and grippy but it's better than the old action stage 3 and 6 puck.
I got an aluminum driveshaft through him too. Made by the driveshaft shop. Aluminum with steel end. Nice unit.
I am pretty happy with the final result, not sure I'm $6800 happy but whatever, it's only money! There where a few issues during the install.
1. The cross member didn't for that well, I needed to open up two of the four mounting holes with a grinder
2. The slave cylinder/ throwout bearing needs to be shimmed to be the right distance from the pressure plate fingers, well the clutch kit didn't come with enough shims nor could you even put that many shims on it to get the 1/8" clearance necessary. I had to machine a .300" shim to go between the bearing and the mounting flange to make it work. The brass piece shown here.
3. the clutch line in the damn clutch line kit wasn't even long enough, it was supposed to be 44" it was...I dont know, significantly shorter. I measured it I can't remember.
4. There is no way to hook the factory speedometer up with the kit or seemingly anywhere.
There are/where also some issues after the install.
1. this thing it loud as hell at idle. Sounds like a box of rocks rattling around.. apparently this is ”normal" and may be caused by a lighter flywheel than the trannys designed for (I'm using a stock w58 flywheel) and or my slight idle misfire.
2. driving at certain rpms accelerating and sometime decelerating the "gear rollover" noise is insanely loud for a tranny I just paid $3200.
Not sure what to do about these two.
3. Leaking fluid at the speedo cable hole. Minor issues but I feel it's one I shouldn't be dealing with.
I did machine a custom adapter to mate the sn95 mustang speedo cable that fits the t56 to the factory mk3 speedo cable so I do have a functioning factory speedometer. It reads about 10mph high but there are speedogear gear options for the cable to fix this
Sn95 speedocable, gear and adapter to mk3 speesocable here
The t56/ bellhousing is about 27lbs heavier than the r154. 160lbs vs 133.
Stock drive shaft was about 30lbs aluminum 13 according to my bathroom scale anyway.
Now my thought on the Tranny otherwise are it's pretty awesome. 1st gears a little tall (2.66 vs the r154s 3.251 )for my 3.91 rear end but it's doable without riding the clutch too bad. I'd like to go the the 4.1 or higher to help with that. It is nice that it'll also do 45mph in first gear though. 6th gear at 80mph is 2500 rpms. the shifter itself also feels 100x better than the sloppy r154s