So, not sure what "gv" means but if you're asking how much a Muncie M21 would cost, hmmm. Go to www.5speeds.com for a better education as I believe they make BRAND NEW Muncies (M22 Rock Crushers) but I suspect for a LOT of $$$. The genius behind them is named Paul Cangialosi, and he knows a LOT. Worth the web time. He has a really great video about installing a Hurst shifter on a Muncie, for instance. In the process, he takes you inside a brand new one and explains in detail how shifting takes place.

I bought my M20 wide ratio about 35 years ago for $200.00 but as so often happens, that ended up turning into another $700.00 worth of gears, and including an align bore of the case. But now, it is pristine. What I do know is that Muncies don't come cheap. But, treated with respect, they usually don't break.

Oh, and by the way, the shift chart is a simple Excel spreadsheet which I can post if interested. I got tired of going to internet sites to try and figure out RPMs so made it one day. You can change any of the variables in yellow and it quickly re-figures RPM's.

 

Also you do not need to compare charts. Unless the transmission say it has overdrive. The final gear is one to one. So in the same cars with the same tires 4th gear in the M20 is the same as a 3 speed manual in 3rd or a over drive 5 speed is in 4th gear. All transmission have a 1 to 1 gear. Dyno testing always happens in the 1 to 1 gear because it is normally the strongest and it loses the least energy because there is very little to flex.

Give GV a call I am sure Chevelle's and Camaros are their bread and butter. Few people like cutting into their 1 gen so I am sure there is a bolt on kit. You may have issues with exhaust depending how it is run.

Any gear less than 1 to 1 like .78 to 1 is an over driven gear. In many cases over driven gears are not for play they are just for cruising. Transmission like the T56 are double over drive and 6th gear is the cruise only gear. One of the nice thing about GV is your in 4th gear (the strongest gear) and the Over drive unit is stronger than the rest of the transmission. I am not saying a transmission like a TKO has a weak 5th gear. It can be designed to be strong but most factory transmission are not designed that way.