Quick NotesWhat we didSwapped the TH350 for a Classic Motorsports Tremec TKO five-speed
Bottom LineThe commute just got better
Cost (APPROX)$3,600 to $4,800
Automatics work great if you want to check out the view during road trips or if you're trying to lock down those e.t.'s with your 1320 brawler. However, there's something to be said for manually shifting a street machine; fact is, you're in total control.
Last month, we introduced you to our latest second-gen Camaro and even outfitted it with a few personal touches. This month we dive head-first into transforming our '73 into the ultimate street machine, trekking out to Classic Motorsports Group in Carlsbad, California.
If you didn't already know, CMG is known for its incredibly complete five-speed conversions and offers three kits (Basic, Deluxe, and Elite) which allow you to pick and choose based on what fits your application and budget. If you're looking to simply upgrade your factory four-speed Muncie, you'll find the conversion can be made with minimal components. And whether you're going for the full-tilt package or tossing the automatic in favor of a stick, a number of options are available, ranging from clutch upgrades to an all-new bellhousing, a hydraulic throwout bearing system, and a 3-inch-diameter driveshaft, along with your choice of shifter assemblies and handles.
Our conversion from a factory automatic to a five-speed required cutting a hole in the tunnel to allow the stick of the Tremec to come through. Additionally, we needed to purchase the clutch pedal assembly and shifter boot, and we had to cut the carpet for the shifter. If this is something you've been interested in doing for yourself, know that the CMG's Elite package is the most complete system out there. Truth be told, it'll take a little elbow grease to get the job done for a first-timer, but it's definitely doable in a weekend. And should you run into a snag, CMG's tech line has the experience and the know-how to get you through your conversion.
PerspectiveThis was our first major modification to the '73 and one we'll never regret. CMG recommended we take it easy for the first 500 miles, so our first leisurely cruise took us through a series of winding turns in our local canyons, giving us the perfect opportunity to row the gears and just get a better feel of the new setup. While we were told that the first few shifts would feel a little tight and a bit on the notchy side, it certainly wasn't the case-at least not in our minds. It was quite the opposite. Each shift felt smooth and went into every gear on command with little effort, and even better, match-revving the rpm on downshifts proved to be solid. Final verdict: The five-speed swap has given the '73 a whole new attitude and feel, and it's every bit more fun to drive.
Use only GM Synchromesh (PN...
Use only GM Synchromesh (PN 12345349) or Pennzoil Synchromesh. It takes 5.28 pints of synchromesh to fill up the transmissionEvery trans includes the wiring for a neutral safety switchAll kits come with a special pigtail connector that clips directly onto the reverse-light switch connectorAll kits come with a custom-built mechanical speedometer cable with integrated adapter and gearElectronic VSS kits are also available for aftermarket gaugesThe Tremec TKO-600 is rated to handle up to 600 lb-ft
Prior to disassembly, Jim...
Prior to disassembly, Jim Goodlad, known as "GM Jim" throughout the Internet, is responsible for R&D and new product design. He started by checking out the driveshaft angle with the suspension unloaded, which showed 20 degrees. To check the pinion angle, he then rotated the driveshaft 90 degrees and found it at 16.5 degrees, giving a total of 3.5 degrees working angle. While this isn't necessary, it's a good practice to follow because it provides a baseline to ensure that the new setup will drive smoothly with no vibration.
Using a trans jack for support,...
Using a trans jack for support, we disconnected the exhaust and removed the starter. Since our transmission lines were pretty beat up, rather than trying to salvage them, we went ahead and cut them. Just make sure to have a pan handy underneath or else you're in for a mess. From there, it was only a matter of removing the bellhousing bolts from the motor (three on each side) and the tranny was out. The passenger side can be a little more challenging due to header and cooler line clearance. The scary part-every bolt was only finger-tight.