With the resurgence in musclecar enthusiasm has come renewed purpose for these iconic American machines. Many of the once quietly garage-stabled classics are coming out from under the sheet and taking to the autocross or road course to stretch their legs. In the 1960s and 1970s traditional musclecars were often offered with either a three-speed automatic or as an upgraded option — the venerable four-on-the-floor.
When looking back at the nostalgia of this performance upgrade we can’t help but turn our attention to the contemporary options for power transfer. The growing enthusiasm for restomodding classic musclecars for modern track day competition and daily use has sprung a market of custom application components like never before.
A modern transmission is one of the primary additions a restorer may wish to install when bringing their classic ride into the 21st century. The folks at Silver Sport Transmissions have engineered several options for the performance-minded builder. One of the big dilemmas encountered by restomodders is the trade off between modern technology and original aesthetics.
Past Problems Solved
In the past, the conversion to a five or six-speed transmission meant a full floor and tunnel face-lift to accommodate for the larger case. Understandably this act is met with reluctance by owners who don’t want to change the retro-styling of their interior. To fill this niche, Silver Sport has developed an application dubbed the Magnum PerfectFit. This fully engineered, all-inclusive kit allows the home builder to shoehorn a TKO five-speed, or a T56 six-speed transmission into their classic muscle car.
We talked to Silver Sport Transmissions owner Jack Silver, and vice president, Jeff Kauffman about the kits to get the inside scoop. “The five-speed has been available for a number of years, it was originally developed at Keisler Engineering and we picked it up. The case gets some machine work to eliminated some of the height for clearance in the tunnel, the shifter mechanism gets offset for the factory shifter location.”
“It’s an all-inclusive kit, you don’t have to run out and buy extra parts, we supply you everything you need,” explained Silver. “Even if you have an automatic car converting to a manual, we supply the pedal package, linkage, bell housing, flywheel, clutch, shifter handle and boots, all the components,” he continued.
Options For Everyone
If you are plagued by noisy and non-economocal high-RPM freeway operation you may lean towards the T56 with its six-speeds. Getting the top-end RPM down to a reasonable level makes an old classic much more livable on a daily basis, and these cars deserve to be driven rather than sequestered away under a tarp.
“The six-speed package is a little different. It requires our fabricated crossmember centersection,” Silver clarified. With the original center section cut out, two side brackets are welded in allowing for a removable bolt-in center. Carrying forward with the improved shifting from the five-speed kit, the factory Tremec shifter is replaced with a short-throw billet unit from Silver Sport.
Regarding the fitment of the Magnum PefectFit kits, car owners are able to retain the factory interior appearance while reaping the benefits of a new transmission. “Unlike other kits on the market you don’t have to modify or cut up your console. It’s going to work, and that’s something unique to our kit. The only way you can tell the difference is if you look at the shift pattern plate, as it has two extra gears on it,” explained Kauffman.
In The Field And On The Track
Silver Sport Transmission conversions have found a market with numerous prominent autocrossers and road racers around the country, we reached out to a few for their impressions on the kits, and how new-found power transfer has changed their rides for the better.
Jimmy Matthews owns a 1972 Nova powered by a carbureted smallblock that he autocrosses extensively. “I autocross and compete in the Optima Ultimate Street Car Challenge, most of the guys I have been running against are big-sponsor cars but we’ve done really well,” explained Matthews.
“We struck up a partnership with Silver Sport and put the transmission in towards the end of the season, with only two races left there was a bit of a learning curve going from an automatic to a six-speed but the car is just stupid-fast now!” he continued.
“The transmission shifts like butter, you could not ask for a transmission to shift any smoother. The power I was loosing through having an automatic to transitioning to this thing made it feel like I had a new motor put in. When you’re swapping gears and in it pretty deep, there’s about 400 rpm between gears.”
“They build a special shift mechanism so you do not have to run an H pattern. When I pull second I literally take the palm of my hand and shove it forward into third, and when I pull fourth it’s straight back, etc.,” described Matthews.
Matthews continued to describe the short throws of Silver Sport’s billet shifter as being around 1 1/4-inch, now that’s tight! While the 2015 racing season is over for most of the country, including Matthews, his Nova is booked for a full season of events in 2016.
Alongside the classic Chevrolet of Matthews is the 1972 Corvette of Scott Feldon, we previously featured Feldon’s car “Black Mamba” on our sister publication Corvette Online. Feldon’s C3 ‘Vette features LS power and a Silver Sport TKO 600 RR five-speed.
Everything that he has promised he has delivered on, it’s been a great transmission. -Scott Feldon
“It was a regular old Muncie four-speed car, but it was a tired, dilapidated car when I bought it. It was not going to hold up to the 600 horsepower I was going to throw at it so it went by the wayside. The good thing about that TKO is you don’t have to modify the tunnel, it fits up in there pretty good. This is the first time I stepped up and bought the road race (RR) with all the upgraded options in it, and it absolutely made a difference. Everything is in place, the console and the shifter fit exactly in the same spot they did originally,” Feldon relayed.
Like Matthews, Feldon is planning his 2016 season of racing and anticipates a full schedule of SCCA, Goodguys, and other events. We wish luck to both racers and hope they find the right gears on the track. If you have a track car project and are looking for a transmission upgrade, talk to Silver Sport Transmissions and drop us a line — we’d love to have a look at whatever you’re working on!