Gear Vendors or swap to better tranny?

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Steve Mcbean

Steve Mcbean

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Hello, fellow Mopar freakazoids.

So, the 318 in my 71 Demon has minor perf. upgrades, but am preparing for more. I have a 3 spd 904 Torqueflite and was thinking of adding an GV unit instead of upgrading the tranny. The price for the GV unit is $2850 while a 5 spd performance tranny from transmissions.net runs around $2600. The rear end will be upgraded from 7.25, to 9 inch or so. My trusty mechanic recommends upgrading the tranny will be cheaper, but I don't see how when the tranny price is close to the GV price and labor hours and modifications seems much lower installing the GV, not to mention the GV allows for 6 speed and gear splitting. I am assuming this question has been asked a bazillion times?
 
The gear splitting function of a Gear Vendors is only really usable if you also buy the controller that does it for you, and even then there's really no good reason to need splitting.
I'm sure you can imagine trying to on/off the GV button while manually shifting.
It's not reasonable to do.

Another thing is that I helped a friend install a GV in his 71 Swinger/904 and we had to cut his floor hump and raise it about 2 inches where the GV unit was going to live.
We also had to re design his exhaust piping because it was in the way.
Then there's the driveshaft shortening involved.

Personally I think the 42RH overdrive trans is a much better option unless you are pushing 400hp or more with that 318.:D.
The 42RH is a 904 with a .67:1 overdrive and converter lockup.
It fits with fairly minor mods to the trans crossmember and bolts right up to the Mopar small block.
Did my Dart with one for about 400 dollars by pulling it out of a 95 2 wheel drive Dakota at the pick a part yard, and that included the automatic shifting for OD and lockup.
When I had the 2.73 gears in the back I ran 2,100 RPM at 80mph and got 25 mpg all day long on the hiway.

Some prefer the GM 2004R trans, but they need to be upgraded internally and need an adapter plate to the Mopar motor.

Some things to consider for you.

A500OD.jpg


ShifterArt.jpg
 
TrailBeast said:
The gear splitting function of a Gear Vendors is only really usable if you also buy the controller that does it for you, and even then there's really no good reason to need splitting.
I'm sure you can imagine trying to on/off the GV button while manually shifting.
It's not reasonable to do.

Another thing is that I helped a friend install a GV in his 71 Swinger/904 and we had to cut his floor hump and raise it about 2 inches where the GV unit was going to live.
We also had to re design his exhaust piping because it was in the way.
Then there's the driveshaft shortening involved.

Personally I think the 42RH overdrive trans is a much better option unless you are pushing 400hp or more with that 318.:D.
The 42RH is a 904 with a .67:1 overdrive and converter lockup.
It fits with fairly minor mods to the trans crossmember and bolts right up to the Mopar small block.
Did my Dart with one for about 400 dollars by pulling it out of a 95 2 wheel drive Dakota at the pick a part yard, and that included the automatic shifting for OD and lockup.
When I had the 2.73 gears in the back I ran 2,100 RPM at 80mph and got 25 mpg all day long on the hiway.

Some prefer the GM 2004R trans, but they need to be upgraded internally and need an adapter plate to the Mopar motor.

Some things to consider for you.

View attachment 1715492577

View attachment 1715492578
Click to expand...

Boom! That's what I was looking for. I read a thread about your experience with GV, but wasn't that some years ago? Have the units not evolved? GV people say there is no need for cutting anymore. They use the term, "massaging". I definitely don't want to have to do cutting or pipe moving. As for the rear end, it won't be 2.73 gears for long, more like 3.55 to 3.73, which is why I looked towards GVs.
 
Steve Mcbean said:
Boom! That's what I was looking for. I read a thread about your experience with GV, but wasn't that some years ago? Have the units not evolved? GV people say there is no need for cutting anymore. They use the term, "massaging". I definitely don't want to have to do cutting or pipe moving. As for the rear end, it won't be 2.73 gears for long, more like 3.55 to 3.73, which is why I looked towards GVs.
Click to expand...

Yea, massaged as in cutting the floor in our case and I can't imagine the 71 Demon being much different.
The dimensions are here: Installation - Gearvendors
And keep in mind your driveshaft needs to stay at the angle it is now. so figure the OD unit needs to stay inline with the trans output the way it is now.
Take into account that it looks like you would need at least 3-4 inches all the way around the top and sides if you measure from the center of your trans yoke about 24 inches back from the 904 tailshaft.
His GV unit with the extension adapter for the 904 put the bulk of the unit where we cut the floor directly under his bench seat.
This should give you an idea of about where the clearance is needed.
 
Steve Mcbean said:
Hello, fellow Mopar freakazoids.

So, the 318 in my 71 Demon has minor perf. upgrades, but am preparing for more. I have a 3 spd 904 Torqueflite and was thinking of adding an GV unit instead of upgrading the tranny. The price for the GV unit is $2850 while a 5 spd performance tranny from transmissions.net runs around $2600. The rear end will be upgraded from 7.25, to 9 inch or so. My trusty mechanic recommends upgrading the tranny will be cheaper, but I don't see how when the tranny price is close to the GV price and labor hours and modifications seems much lower installing the GV, not to mention the GV allows for 6 speed and gear splitting. I am assuming this question has been asked a bazillion times?
Click to expand...
May I ask why you want this upgrade? In my opinion, if you plan to do a LOT of highway driving, the extra gas mileage and decreased RPM might be worth it to you. Your choice of course, but if that is the reason, you can buy a lot of gas for $2800. I thought about an overdrive for my car, but I can't force myself to spend that much money to get better gas mileage for the little highway driving I do. Just think about it.
 
harrisonm said:
May I ask why you want this upgrade? In my opinion, if you plan to do a LOT of highway driving, the extra gas mileage and decreased RPM might be worth it to you. Your choice of course, but if that is the reason, you can buy a lot of gas for $2800. I thought about an overdrive for my car, but I can't force myself to spend that much money to get better gas mileage for the little highway driving I do. Just think about it.
Click to expand...

I daily drove my Duster for about 12 years. Thought about buying one of those OD units but I did the math and I'd have to daily drive it for about another decade to break even on it.
 
i know three guys running the GV OD units and they love them.. turns their 3.55 gears into a 2.76 ish gear. two guys with challengers it went right in no issues. the one challenger owner has to have 50,000 miles on that thing and its been flawless. the third guy has a dart and only needed to dimple the floor in one spot. not cutting of anything.

hell it seemed like most of the cars in drag week were running them also..

only thing i wish is that they would make an option for a better OD ratio.
 
gear vendor in my 70 dart did not have to cut the floor just a few smacks with a hammer to clearance , also could not use an x pipe exhaust needs an H pipe . shifts are fast and hard .
 
have you read these?
Overdrive tranny in an A-body
Has anyone successfully used the USCartool A500 Crossmember?
727 46RH conversion coming
GearVendors install
A500 42RH Crossmember template?
Silver Sport A41 4speed auto

they are all good options. just need to know what you want and how much work you want to put into it. i like the silver sport setup. i was even willing to do it after they said their kit wouldn't fit my 273 because the starter is on the wrong side and they couldn't match the flex plate bolt pattern :rolleyes:... but now i'm back on GV.
 
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