Resources:
- Gearstar Performance Automatics (click to visit)

Update 8 : A Transmission For The Coupe

Let’s start this article by getting the fundamental decision out of the way. That is, did we want a manual or automatic transmission? Answer: Yes

Ok, so a binary answer isn’t the appropriate answer but, in fact, a lot of us want both. The reality is that we have to choose one or the other. The manual shift junkies will tell you that there’s really one choice if the ultimate fun factor is what you’re after. Automatic aficionados will argue that you don't give up anything if you select the right transmission package. We won't be debating the merits of either argument here. What we do know is that we considered how the car is going to be used and the car itself in making our decision.

While our project car would deliver lots of opportunities to “row through the gears”, it will likely spend most of its time at highway speed. That’s excuse #1 ( er, reason…) to go automatic. Reason #2 is directly related to the congested foot space area in a Deuce and reason #3 is related to secondary drivers. Enough said. Automatic it was to be.

So, with that decision behind us, we made the decision to have a transmission built for us rather than grabbing something out of stock or installing a cleaned-up unit with an uncertain history. After all, when making this decision, we were having our engine built and wanted the same kind of care and attention put into the unit behind the engine that is instrumental in controlling the application of all that good stuff generated by the engine. In our case, that good stuff turned out to be 439 hp and 467 lb-ft.

As for variety of transmission, we were certain that we wanted decent highway RPM so we settled on the refined version of the 700-R4/4L60 series. Specifically, the 4L60E. As this version does away with the throttle valve (TV) cable, a transmission control system is required. The control system allows for control of shift points, shift quality, and converter lockup. It also eliminates what can be problematic throttle cable adjustments.

With projected engine specs in hand we contacted Zack Farrah of Gearstar Performance Transmissions of Akron, Ohio. Gearstar manufactures its performance automatic transmissions to the specifications of your engine taking into consideration horsepower and torque, rear gear ratio and intended application. Zack recommended their Level 4 version 4L60E with a HGM Compushift II standalone control system. The HGM Compushift II works in conjunction with a linkage-controlled throttle position sensor for carbureted applications like ours.

Gearstar Level 4 4L60E

HGM Comoushift II


Gearstar Performance Transmissions custom builds each transmission to the customer’s exact needs and for their specific application. "Transmissions are overbuilt and underrated". Each transmission is DYNO tested, as a package, to the equivalent of 100 miles on the road. Every Gearstar transmission is built by only one of their Master Technicians from start to finish. The Master Technician who builds the transmission is also the customer’s technical advisor and they encourage every customer to call to speak with their builder.

Transmission being test on the Superflow Dyno

Being crated for shipment

Ready to ship and exactly as we received ours


Here are the details for our transmission:
- Rated for 600 HP / Up to 650 ft-lbs Torque
- 10” Custom-built lock-up converter with billet cover / stall: 2800-4000
- Master overhaul kit with Raybestos generation II racing frictions and hardened kolene steels
- Wide carbon fiber 2-4 Band
- 2 Transgo recalibration shift kits with Shift Command
- Original equipment-style filter
- New internal wiring harness with TCC Solenoid
- New shift solenoids
- New EPC solenoid
- New PWM solenoid
- New 3/2 control solenoid
- New manifold pressure switch
- New electronic speed sensor
- Corvette servo
- New valve body separator plate
- 4th gear super hold servo
- New Torrington bearings
- Complete bushing kit
- Thrust washer kit
- New 28-element input sprag
- High capacity 10-vane pump assembly with new rotor and slide
- Hardened stator shaft
- New vanes and hardened rings
- 0.500 Boost Valve
- Updated pressure regulator valve
- Extra capacity 3-4 clutch drum assembly with high-rev spring kit
- Reinforced input drum
- Heavy-duty hardened rollerized sun shell
- Five-pinion heavy-duty steel planetary gear sets
- New polished aluminum transmission pan
- 30,000 GVW Hayden Transmission Cooler

Custom manufacturer of high performance transmissions
"Our company was built on repeat business and word of mouth"

As the project progresses you see and hear a lot more about our Gearstar 4L60E