Has anybody on the board tried out the m-21 with the 4th gear overdrive. You can get the gears for about $400.00. It's suppsoe to get you about a 13% overdrive, which isn't bad considering you don't have to chop up your tunnel. Here's a link to a guy that sells the complete unit's.
The drop in rpm's between shifts would be terrible I would think. That is too much ground to make up with only 4 gears.(2.20 down to .85)
True that would help but I would like to see the drop in rpm's if you were just driving normally and shifting at 2500 or so.
I didn't see anyother posts on this- I searched and found this from last year. Anyone try one of these overdrive M21's? 4th ends up as a .87 OD. Thanks, Eric
You could always add a Gear Vendors overdrive unit. I have one sitting in the garage and I'd love to put it on the GSX but it is desinted for the F250 with diesel fuel what it is today. Brian
I did a Tremec TKO600 5 speed. The tunnel mods weren't bad at all. A 71 auto crossmember works perfectly w/no mods. Trans is a lot of money though. But here's the deal, I sold my muncie for $900.00 & the new trans was $1975. It was the best upgrade I did to the car. I can cruise the highway @75mph spinning 1800rpm, w/3:23 rear.
http://www.riversidegear.com/categories/muncie-4-speed/products/product-166.html did you see this one? http://www.m-22.com/m22/