[Socrates]

Here we have perhaps the saddest site seen in a “performance” car.


No, it’s not the dirty carpet or the worn pads, it’s the missing pedal!


In the little spare time I had between writing 4 stem cell and regenerative medicine research articles, and by way of more then a couple sleepless nights, I’ve been installing a 6 speed manual transmission in a car that, 45 years ago, hit the road with only 2 forward gears to match these 2 lowly pedals. With the science and science writing finally complete and while still in a writing mode, I have compiled a write-up for installing a Viper T56 in an early A-body, in this case a 1966 LeGTO. Sure, a T56 swap has been done before and done quite well. However, there isn’t a good single source online for all the info for us BOP guys to refer to, and for covering some of the little “gotchas” that sneak up in such customizations. The little things often not covered in a brief post can and will turn 2-3 week projects into 2-3 month+ battles while waiting for parts, for oddball customs, and other unexpected events. My swap was testament to this fact! I spent months researching an ideal pile of parts for the swap, yet still gave my UPS guy a workout sending parts back and forth to Summit, and waiting weeks for backordered pieces I couldn’t have anticipated…

By the request of a few friends here also wanting to perform a T56 swap, I’ve made this write up lengthy and detailed as to include many steps to hopefully help more people at various stages. I’ve even documented the basic removal of the automatic transmission steps and have included a guide for installing a LT1/LS1 to supplement the full Viper T56 install, as broken down into sections listed in this table of contents:


Auto-to-T56 Manual Transmission Swap Table of Contents:

A.) Removing the Automatic Transmission

B.) Viper T56 Installation
……1 Viper T56 Basics:
……2 Hole in the Floor
……3 Pilot Bushing, Flywheel, Clutch and Bell Housing Install
……4 Cut Down Input Shaft
……5. CSC Modifications
……6. Clutch Master Cylinder
……7. Clutch Master Cylinder and Firewall Plate Modifications
……8. Custom Dowel Pins
……9. Hoisting the T56 Into Place
……10. Custom Cross Member
……11. Drive Shaft Safety Loop
……12. Fluid Fill
……13. Driveline Angles
……14. Trans Tunnel Fabrication and Install
……15. Interior and Shifter Boot Install

C.) Tips for Installing an LT1 or LS1 T56

D.) Part Numbers and Prices


I initially happened upon a great deal on a low mileage 1997 LT1 T-56, then quickly sold it in favor of a 2006 Viper T56 with just over 18k miles on it as the superior platform for my planned build. Where a LT1/LS1 T56 was built to handle the ~300HP of the child-seat-ready F-body’s power, the 3rd gen SRT-10 Viper T56 is built to hold the 505 cubes, 510+HP/535+ft/lbs Viper V10 in a max effort, purpose built race vehicle. The Viper T56 is built to handle the 0-60 in 3.5s and a standing quarter in 11.5s at 124mph in a automobile that can pull 1.05G on a skip pad, all numbers I aspire to approach with my own car. This is a trans worthy of a big cube Pontiac engine.

Before someone asks, I was tempted to go with an aftermarket T56 or an uber nice new TR6060, or even a TKO600, although the price for those transmissions alone are more then what I paid for every part of my swap, from the trans to new flywheel to custom driveshaft. The Viper take-out conversion made more sense to me. In all, after selling my original trans setup and other original parts, I was able to put the Viper T56 in my car for $980 (breakdown later).


Here are a few shots of the noble beast I’m currently working on, a 1966 Pontiac GTO clone. This build is primarily aimed at making the car comparable to modern sports cars in comfort, safety and performance, while retaining the classic style and aura.













With no further ado: