My vert is used for just cruising around on a nice day. Has 2.94 rear gears( original 440/727 in it). Have always thought it would be fun to up the rear gears to 3.55 or 3.23, but would like a good hwy cruise RPM without working the motor..
Tell me about your gearvendors O/D?? install, dependability, servicing, any problems?? Thanks

I've had a GV in my e-body for 4 years now. It was a easy install with slight dimpling of the floor hump in two places, minor electrical wiring, and having the driveshaft shortened. You will have to remove the tail shaft from your current trans and install the supplied adapter. FWIW the OD is .80 to 1 so not as much OD as some other options out there. I use my car like you describe and have about 3.5K miles on it so far with NO issues.

As already mentioned, those are modifications you will have to perform. I did mine in a weekend plus a Monday for the driveshaft return. Ran the foot switch next to the hi-beam, the toggle into the center console. I have a 440/727 with 3.55s and I can drive 80mph @2200rpm. Had it in there since 2007 and have about 7000 miles on it. She is a weekend car. The only thing I goofed on was the GVO sat up against my H-Pipe for 2000 of those miles and the gasket burned out. They sell em for 6 bucks each and I replaced it already. The downfall you will realize is that you have to to run Mopar Manual Synthetic 75w85 at $15 a quart. I did some digging and found that MT-85 will work just as good from Redline and I bought a few bottles from eBay.

I still can't get the whole synchronization down of shift, OD, shift, OD, to split the gears but the 4th gear overdrive works fine for me

I've had a GV in my challenger since 2005. As said by an earlier poster, pretty simple install.
I'm running 3.91's. Cruise down the SoCal freeways at 70-75 at 2500-2600 rpm.
Absolutely love it.
G-bob's Gearvendors install

I've got one also...Works great one of the best investments for driveability...4:10 dana, 727 and a high stall converter..Ends up with a 3;21 ratio in OD..

They have a fantastic rep, castings are made in England and all machining is done in their U.S. plant. If you plan to keep your Mopar for the long haul, then it is a good investment.

there is a very interesting SAE paper where a group in England decided to find out what RPM led to best fuel economy in real world driving

to find out they installed three Gearvendors style OD units in series in place of the driveshaft of an English Ford Escort and drove it at different speeds on different road conditions and loads

DabeastII has one on his small cam 512 69 superbee and it is an awesome set up was easy to install on the tranny (I helped)

How heavy is the final section. Looks like a long lever arm with no support?

The OD unit itself might weigh 15-20 lbs. The new tailshaft housing/ adapter has about 4 ribs cast into it, and is plenty strong enough to handle that weight. I have had 3 GV overdrives in 3 different vehicles, and they are VERY heavy duty units.

I haven't owned one but I've driven several cars with them on some long haul rides, If I were building an OD automatic car I wouldn't go any other way than the Gear Vendor unit, they take MAJOR abuse and are a dream to cruise at highway speeds even with a fairly deep rear gear.

For an OD manual trans and a 100% bolt in setup, there's no other choice than the new Passon 5 speed (see pic), they are a BEAUTIFUL piece of workmanship!

That's a nice looking unit...Scott are you using that in one of your cars ??? I hope to try one of those out in the near future...

It's going in my yellow 340 Duster (behind it on the rotisserie). I have limited time to work on it due to my carb business sucking away most of my time so I pick at it when I can. My target completion date is "Summer" of 2014. Most of the major sub assemblies are done now but still a long way to go getting it all put together. We'll see how it goes.

I did the 4L60E overdrive swap in my 69 roadrunner and even though its more expensive then the gear vendors I like it a lot!

If your upgrading the transmission, is the GV still a better option than a 518.
Is the attraction the ease of installation, it's about $3k for the GV right?

Have one in my 67 Coronet 493 with 3.55 gears. Makes cruising down the highway nice as it puts me in the 2.80 something gear range.

Have one in this car http://youtu.be/Pc-4z5WrNwc 74 cuda 408 stroker and love it. Easy to install, slight dimpling in floor and minor wiring. Evidence above of abuse. Even shifted into 2nd over at the strip WOT,, no gain on my combo but good testament to the shift quality and durability. Wanted to go 518 but they were pretty hard to find at the time for any kind of fair $ and the GV 727 combo is proven tough.

I hear a lot of concerns on driveline angles but I had no problem getting mine good and its one of the smoothest 11 sec cars I imagine you'll see. Well as far as old muscle goes anyhow

One of my longterm projects is installing the Laycock-deNormanville OD in my Gremlin. (Later Gearvendors units are virtually identical to the LdN unit - I can even get parts for it from GV!)

Lucky for me, the LdN unit was a factory option in '75 and '76, even though my Gremlin is a '70 it's still a bolt-in process!

I'm curious to see how it'll perform as it's a three-speed with the OD, and only a 3.08 gear. The steepest gear one could order with the unit is only 3.08.