When was the last time you saw an automatic car smoke the manual drive competition on a road race circuit? Well, it probably was smoking from the overheated transmission fluid. It's no secret that manual transmissions dominate the road race and autocross venues and are also quite popular at the dragstrip. Our reason for the swap into our '66 Mustang is for all of the above, and the general fun-to-drive factor that comes with a clutch.
Project Street Fighter Mustang started out as an inauspicious '66 coupe whose body panels concealed a straight-six auto-driven drivetrain. The rest of the car was as stock as the powerplant. Over the months, we've been updating it. You may have caught the Chassisworks front and rear suspension overhaul and the big, bad Smeding 427 Windsor build. Keeping with the hard-core road race theme, we wanted to back the small-block with a manual transmission.
When it came time to choose a transmission, we wanted something modern that required minimal modification to the floor and other related components. We knew manual transmission swaps were something Keisler specialized in. They've got several options when it comes to GM, Ford, and Mopar conversions. In our particular case, we wanted something that would fit under the floor without modification. New to Keisler's lineup is their T45-RS Perfect Fit kit. Keisler has modified this late-model Mustang transmission to withstand more power and more abuse than the stockers. They also adapt the transmissions to use a Toploader bolt pattern to make it easy to adapt to standard bellhousings. If you're doing an automatic-to-manual swap, then Keisler supplies a bellhousing to use. We needed everything, and that's what our kit included. They also have T45-RS PerfectFit kits for popular GM models.
First to mate to the engine is a Ram billet steel SFI-approved flywheel. The clutch assembly also came with Keisler's new Pro Touring series clutch disc and pressure plate. This combination is aimed for street use, but is definitely capable of holding the power our Windsor puts out. It's a ceramic material disc that is good for 650 hp, well higher than the engine produces. The clutch is actuated by a hydraulic throw-out bearing. We wanted to use their hydraulic setup because of its compact design and modest pedal effort. The kit contains a Wilwood master cylinder with a remote reservoir that uses the factory clutch linkage hole that is on every Mustang, thanks to Keisler's billet firewall adapter. The transmission's modifications by Keisler makes it much more driver friendly because they've fixed some of the issues this model is notorious for, like the shifter popping out of gear when in reverse.
The transmission crossmember greatly improves the strength of the old Mustang's floor, while giving the tailshaft some place to rest. It's made of mild steel and powdercoated black for a clean look. The crossmember doesn't require floor modification to fit, but it does have two sets of bolt holes to improve rigidity across the tunnel. You will have to drill these holes out to match the crossmember's holes. There are two other places that need some modification, but they are extremely easy. The transmission tunnel has a support that hangs down about an 11/2 inches that needs trimming, and also the shifter opening needs to be adjusted. Keisler includes templates for all these cuts, so don't worry, there's no guessing. They also offer the option to keep the shifter hole in the same place, and to modify the engine mount holes to aim the transmission to the shifter hole. We're using Chassisworks motor mounts that were just too pretty to cut, and the amount to remove around the shifter was minor.
Once all of the clutch-related parts were secure, we attached the bellhousing temporarily
On the transmission side, we depressed the throw-out bearing, simulating the clutch being
Here is the hydraulic assembly. The master cylinder is made by Wilwood with a special adap
All Mustangs have this hole (seen here as a metal plug) located just under the brake maste
The Keisler-supplied backing plate can be held against the firewall adjacent the master cy