Ok, the best trans ever part may be up for debate but I wanted to show you guys what I am working on for an all wheel drive muscle car I have been building for the last few years. The T-56 6 speed is one of the most popluar performance transmissions ever build. They are touted to handle 1000hp and shift as smooth as silk up to and over 7000rpm. I remember this question being asked on here before with no clear answer so I wanted to do that now. Now i know that some are going to say that a car trans will not live in a big 4x4, well I have no idea on that. Just wanted to show what I am up to.
I started off with a T-56 transmission and thinking that I may run it in a divorced setup but really did not want the length, extra parts or weight of all that (I am obsessed with weight on this build). What I ended up building is a hybrid of a few different applications of the T-56. You can also build this one 2 different ways depending on what output spline you may need, 27 spline or the big 32. The 27 will be easier since you can pick up just about any LT1 or LS1 T-56 and change the tail shaft and shifter. The 32 spline like I am doing is a bit more difficult and costs more, but is WAY stronger plus has better synchro/blocker rings to improve high RPM shifting. The key to this whole thing is a relatively easily obtainable C5 corvette T-56 tail shaft and a mid mount shifter which is available from Keilser for $400
What I am doing is using a C5 T-56 with a Chevy SSR main shaft (32 spline) and 1st gear with its retainer with a mid plate from a Viper. The C5 gives you the better synchro's vs the older viper/ls1 style T-56. Wrap up the trans with the C5 tail, then adapt another tail to that to make up some room. I am using the tail shaft from a 545rfe auto trans because, well I had one laying around and it is just about the right size, shape and has the NV 6 bolt transfer case flange at the back. Plus it has a transmission mount cast into it unlike the C5 tail. The C5 T-56 is usually a little cheaper as well since it is not as popular in the aftermarket swap arena.
I expect to be done with this in about a week. I am waiting on a few pieces of 3/4 thick aluminum so I can make some adapter plates both for between the tail housings and the transfer case because I need to flip my nv147 t case to the passenger side. I will put up a few shots of it when it is all done
Here is the stock C5 T-56
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C5 main shaft next to the 32 spline SSR main shaft
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Here I have my T-56 assembled with the Viper mid plate, C5 input shaft and SSR main shaft. I left all the other parts out because I am still in mock up and a 55 pound transmission is a lot easier to move around
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Here is the 545rfe tail sitting on the back. Both tails have a large indexing ring that I will cut holes in the 3/4 aluminum to center everything
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and my hybrid T-56 with the NV147 transfer case which has a 32 spline input shaft swapped into it. The 4 bolt flange you see is where the mid shifter will mount. Usually that is just for an inspection plate
![Image]()
I started off with a T-56 transmission and thinking that I may run it in a divorced setup but really did not want the length, extra parts or weight of all that (I am obsessed with weight on this build). What I ended up building is a hybrid of a few different applications of the T-56. You can also build this one 2 different ways depending on what output spline you may need, 27 spline or the big 32. The 27 will be easier since you can pick up just about any LT1 or LS1 T-56 and change the tail shaft and shifter. The 32 spline like I am doing is a bit more difficult and costs more, but is WAY stronger plus has better synchro/blocker rings to improve high RPM shifting. The key to this whole thing is a relatively easily obtainable C5 corvette T-56 tail shaft and a mid mount shifter which is available from Keilser for $400
What I am doing is using a C5 T-56 with a Chevy SSR main shaft (32 spline) and 1st gear with its retainer with a mid plate from a Viper. The C5 gives you the better synchro's vs the older viper/ls1 style T-56. Wrap up the trans with the C5 tail, then adapt another tail to that to make up some room. I am using the tail shaft from a 545rfe auto trans because, well I had one laying around and it is just about the right size, shape and has the NV 6 bolt transfer case flange at the back. Plus it has a transmission mount cast into it unlike the C5 tail. The C5 T-56 is usually a little cheaper as well since it is not as popular in the aftermarket swap arena.
I expect to be done with this in about a week. I am waiting on a few pieces of 3/4 thick aluminum so I can make some adapter plates both for between the tail housings and the transfer case because I need to flip my nv147 t case to the passenger side. I will put up a few shots of it when it is all done
Here is the stock C5 T-56
C5 main shaft next to the 32 spline SSR main shaft
Here I have my T-56 assembled with the Viper mid plate, C5 input shaft and SSR main shaft. I left all the other parts out because I am still in mock up and a 55 pound transmission is a lot easier to move around
Here is the 545rfe tail sitting on the back. Both tails have a large indexing ring that I will cut holes in the 3/4 aluminum to center everything
and my hybrid T-56 with the NV147 transfer case which has a 32 spline input shaft swapped into it. The 4 bolt flange you see is where the mid shifter will mount. Usually that is just for an inspection plate
