b5 blue
Member
Thinking about installing a gear vendors overdrive in my 71 roadrunner. Anyone install 1 ? Pros and cons.
When I finally get to restore my 70 Road Runner, I will put an overdrive in it since I am planning to drive it quite a bit, including highways.
Forgetting about price for a moment, my top choice based on what I had seen WAS the Gear Vendors overdrive (about $2900). With a 4 speed, it would bolt in replacing the trans tailshaft. According to what I read, the only modifications needed are a possible dent in the transmission tunnel, as well as a shortened drive shaft. My only concern I had was that the overdrive was .78 to one - not super steep. This means that 4.10's drive like 3.20. Not bad. Also, all I have heard about them is that they are essentially bullet proof.
...But then I heard about the Passion 5 speed overdrive. It is called an A-855 and literally bolts in place of a A-833 4 speed. Zero other modifications. It is VERY expensive at around $4500, but it is really cool sounding in my opinion. Also the final drive ratio is .70 to one. This means those same 4.10's drive like a 2.87. This means you lower your effective RPM even more when on the highway.
Please note that I do not have any personal experience with either, so the above is what I have found based on research, not based on actual installation and driving with either...
If price were no object (and I am not even sure you can get the A-855 yet), then IMHO the A-855 is best. Second place would be the Gear Vendors. When you factor price in, the decision gets harder...
I have a few GV's in different apps, have one that is over 20 yrs old, and as a installer i have done many over the years in many different uses. Other trans are only a od gear added at the end.
The gv is a gear you can use between every gear you have now in your trans.
You'll find it much better than a 4sp or 5spd swap, when you can split 1st, 2nd, and then 3rd gear depending which trans you have.
May be a little more but it is another gear after your 3 giving you more options.
SMR transmissions offers the "shortie" Gear Vendor overdrives for Mopar automatic transmissionshttp://smrtrans.tripod.com/smrtransmissionsintro/id32.html
What about an aftermarket 5 or 6 speed with deeper gears and a 1:1 high gear ratio? Then you could run 2.94's or 2.76's and still have the torque multiplication in the lower gears.
http://www.summitracing.com/parts/rmg-7031710c/overview/make/dodge
The only con I've read about is price. All I've seen has been GOOD feedback, so they are probably worth it.