More Gears: A Six-Speed Manual Swap Option for C3 Corvettes

Get more from your classic Vette’s engine and leave your four-speed in the seventies where it belongs!

Here at CorvetteForum, we love C3 Corvettes. We’ve really been drooling over them lately. Late C3s are plentiful, inexpensive, and easy to modify. One of the weaknesses of these cars, though, is the four-speed manual transmission, which was pretty archaic by the end of the car’s run.

That is, of course, if you were even lucky enough to get to row your own gears in the first place. By the end of the line in 1982, no manual transmission was even offered. Is it worth the effort to swap to a four-speed?

You could always swap in a more modern transmission, but that would destroy the look and feel of the car. The C3 Corvette is all about the experience and the mood.

What if we told you there was another option? What if we told you that you could put a six-speed in your Corvette and that it would look and feel like the original four-speed?

Silver Sport Transmission has you covered with their Tremec Magnum 6-Speed PerfectFit kit. It’s a comprehensive upgrade that’s been carefully designed to preserve your C3’s character while dramatically improving driveability.

The only visual difference from stock is a shift-pattern plate, in the original factory style, showing six gears instead of four.

It’s a fully-synchronized transmission, meaning shifts are silky-smooth and there’s no gear noise under normal operation. There is also a hydraulic clutch option to make driving your C3 even better.

Talk about transmissions and more on the forum.

At roughly 60 MPH in fourth gear, you’re turning about 2,500 RPM. In fifth, you’re just under 2,000 RPM, and in sixth gear, you’re under 1,500 RPM! That’s great for fuel economy and also gives you room to add a shorter gear for better acceleration.

You can find out more information on this conversion from Silver Sport Transmissions.