Hey all, Decided on a Gear Vendors unit for my '72 Skylark with a TH350 and 3.42's. 3000rpm at 65 isn't gonna cut it. Are there any tips & tricks I should keep in mind before starting? The only thing I can't do myself will be having the driveshaft shortened. It doesn't look like room in the tunnel will be an issue, and if there is I have a BFH. They don't have instructions I can look at on their site, obviously, so the only part of it I'm not sure about is how it senses driveline speed. Does it simply read the transmission shaft speed to determine shift RPMs? Or another way? The reason I ask is because my trans drive and driven gears are wrong so the speedo reads way higher than actual speed. Is that going to be a problem? Thanks!
When you order it, they will ask you for tire size and axle ratio. You will no longer use the speedometer drive/driven gears in the transmission. They give you a short speedo cable with an electric speed sensor at the end that goes in the GV and your factory cable goes to that. You will be happy with the GV unit, your wallet not so much! You will have no regrets.
Yeah... the $$. That's the part I'm stumbling over. I'm sort of in a hurry (need it done before June) and finding a trans, getting it properly rebuilt, swapped in and correctly hooked up will take much more time and effort than the GV. And end up costing more. At this point in life, I'm all about simplicity and convenience.
Joe, I have a pdf of the Gear Vendors Manual. It is an old one from 2006, but the instructions are the same for installation. The only critical step is shimming the coupler. When you remove the extension housing of the transmission, and install the GV adapter, there is a coupler that slides onto the output shaft of the transmission. The end of that coupler takes round shims (supplied). The idea is to shim until the end of the coupler is even with the gasket surface of the adapter. Here is a page of the manual that discusses that step, There is a signal generator that goes inline with the speedometer cable. That is what senses your speed. Other than that, the install is very straight forward. I'm sure you will get a manual with your unit. The control unit they use now is made by MSD. All you need is the correct DRIVEN gear for the unit. If you want the entire manual, just send me an e mail (address in signature) and I'll send you the pdf.
Thanks Larry....appreciate it. I figured out some of it, but was concerned whether my incorrect speedo gears would be a problem. I didn't know how the GV attached in that regard. They ask you for all the pertinent data so I assume it comes with the correct gear? Will a mismatch already in the trans screw things up? Previous owners put 3.42's in and skipped that step.
Joe, The GV has it's own speedometer DRIVE and you have to provide the correct DRIVEN gear. The GV has a 15 tooth DRIVE gear. The chart I pictured lets you look up the correct DRIVEN gear for your car. The transmission speedometer set up does not get used.
