Gear vendor, under overdrive for 727, Anyone have one

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mistreta

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Thinking about a Gear vendor under, overdrive for my 727 in my 408 Duster. OK around town
355 not a long haul gear. Sounds like a good upgrade.
 
I have a GV on my aluminum case 4-speed....and one in the box for the 727 that is going in my next project. It will split shift like the dump truck I drove in my twenties, but I like it for anytime over 55mph.....especially on the 4-lane doing 65-70 @ 2200-2400 rpm.
 
HemiDenny said:
I have a GV on my aluminum case 4-speed....and one in the box for the 727 that is going in my next project. It will split shift like the dump truck I drove in my twenties, but I like it for anytime over 55mph.....especially on the 4-lane doing 65-70 @ 2200-2400 rpm.
Click to expand...

I may have to look into one for the dart
 
mistreta said:
Thinking about a Gear vendor under, overdrive for my 727 in my 408 Duster. OK around town
355 not a long haul gear. Sounds like a good upgrade.
Click to expand...

The ratio of overdrive gear vendors provide is not really worth it. I drove a buddies 727 with gear vendors and was disappointed with the rpm drop when it was engaged.

If you really want to enjoy your 408, swap in a built 200R4 with a high stall lock-up torque converter. It's like having a 5 speed automatic. The 200r4's first gear is .25 lower than a 727's, and the overdrive is .67 to 1.

There's a night and day difference between the two ways to add overdrive to your old Mopar. If you drove your car with each set-up installed, you wouldn't ever consider the gear vendors.
 
I have a GV unit in my Barracuda. My combo is commando+ 273 build with late model 904 based transmission W/custom lockup converter. I had my 8 1/4 shurgrip built with 3:73 ratio and will be running 245-60R-15 on 6"stock rally wheels. I expect to be running about 2400 rpm at 70 mph.
Don't know if that is good or bad but those are the cards I chose to play.
 
Just for discussion....the GV reduction is .78.....takes my 4:30s down to 3.35.
How much lower do you need in a hot rod?

I bought my second one second hand / but still in the box....delivered to my door for $1500. There are used ones out there if you want to save some bucks.
 
jbc426 said:
The ratio of overdrive gear vendors provide is not really worth it. I drove a buddies 727 with gear vendors and was disappointed with the rpm drop when it was engaged.

If you really want to enjoy your 408, swap in a built 200R4 with a high stall lock-up torque converter. It's like having a 5 speed automatic. The 200r4's first gear is .25 lower than a 727's, and the overdrive is .67 to 1.

There's a night and day difference between the two ways to add overdrive to your old Mopar. If you drove your car with each set-up installed, you wouldn't ever consider the gear vendors.
Click to expand...

Interesting, Thank you for your input. The 200R4, what is that used in, is it a bolt in replacement for a 727?
I would like to know more.
 
HemiDenny said:
Just for discussion....the GV reduction is .78.....takes my 4:30s down to 3.35.
How much lower do you need in a hot rod?

I bought my second one second hand / but still in the box....delivered to my door for $1500. There are used ones out there if you want to save some bucks.
Click to expand...
What size rear tires do you have?
 
have a few friends with them,... all of them love it.. will turn those 3.55 gears in to what? 2.76 i think.. awesome for the highway
 
mistreta said:
Interesting, Thank you for your input. The 200R4, what is that used in, is it a bolt in replacement for a 727?
I would like to know more.
Click to expand...


The 2004R is Gm overdrive automatic. I have one in my '69 Barracuda. I absolutely love it!! It requires an adapter plate sold by numerous companies. It is not a bolt in replacement. It also requires minor trimming of the upper trans cross member and changes in driveshaft length. The TV cable connects to the carb (adapter bracket so you won't need the Mopar linkages.
I installed mine complete for about $1800, I did all the labor.

Treblig
 
408...hmmm,You should be able to boil the hides with 3.23's, which are a nice cruz gear.
Maybe try a 3.23 gear first...you might be happy right there.I know that doesn't answer your question about a GV,just a thought
 
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HemiDenny said:
Just for discussion....the GV reduction is .78.....takes my 4:30s down to 3.35.
How much lower do you need in a hot rod?
Click to expand...

More than that for my tastes. Heck, even 3.23 are pretty wrung out at 70 mph with a 28" tall rear tire. With 3.91's a .67 overdrive knocks the revs down nicely to an effective 2.62's ratio, and a lock-up converter adds a nice rpm drop too.
 
Treblig said:
The 2004R is Gm overdrive automatic. I have one in my '69 Barracuda. I absolutely love it!! It requires an adapter plate sold by numerous companies. It is not a bolt in replacement. It also requires minor trimming of the upper trans cross member and changes in driveshaft length. The TV cable connects to the carb (adapter bracket so you won't need the Mopar linkages.
I installed mine complete for about $1800, I did all the labor.

Treblig
Click to expand...


Or you can use a bellhousing and adapter to bolt it to your motor. The car does need some modifications, but the floor pan remains the same. US Cartool makes a crossmember kit for them now.

200R4 3 (Large).jpg


Heart (Medium).png
 
jbc426 said:
More than that for my tastes. Heck, even 3.23 are pretty wrung out at 70 mph with a 28" tall rear tire. With 3.91's a .67 overdrive knocks the revs down nicely to an effective 2.62's ratio, and a lock-up converter adds a nice rpm drop too.
Click to expand...

That is a great option too......especially for hyway use.
 
jbc426 said:
Or you can use a bellhousing and adapter to bolt it to your motor. The car does need some modifications, but the floor pan remains the same. US Cartool makes a crossmember kit for them now.

View attachment 1714994866

View attachment 1714994867
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Don't forget you have to cut down the tunnel support structure and reinforce it. I considered that transmission but my car was cut and buffed and too far down the road for that option. That mod is best done before paint.
 
DesertRat said:
Don't forget you have to cut down the tunnel support structure and reinforce it. I considered that transmission but my car was cut and buffed and too far down the road for that option. That mod is best done before paint.
Click to expand...

I'm a believer in reinforcing the car as much as possible unless it is some kind of numbers matching car for sure. I welded in US Cartool subframe connectors and their full chassis stiffening kit in addition to welding the torsion bar crossmember solidly to the floor, thinning it out in cross section and reinforcing it with my own fabrication.

The shock towers on the late 60's A-Bodies are just hanging in the air with a few spot welds at the top to hold them to the inner fenders. I welded mine solidly to the inner fenders from the frame rail up, and have the under fender bracing welded in too. It makes the car feel WAY more solid on the road.

I painted my floor and trunk with that roll on bed liner for durability under the carpet. If you are interested in painting the floor and undercarriage body color, you sure would have to do the modifications before paint. I'll spray them all body color once I finally get the exterior paint done.
 
branded209 said:
Nope at most a little dent
Click to expand...
I now have mine installed and tested. I had to lower the transmission crossmember 1 inch to clear properly. But with 3:73-1 gears and 275/60/15 on 8" wheels I am at 2300 RPM at 70 mph-with a lockup converter. It runs well there and the control is fantastic.
 
I also have a 408 stroker (465 hp) and was thinking of either running 323 gears or getting a Gearvendor and going 391’s.

going to be running a 295 tire, if I can brake traction easily with the 408 and the 323 I’ll just save the 3k, not doing to much high way driving.

What do y’all think?
 
jbc426 said:
I'm a believer in reinforcing the car as much as possible unless it is some kind of numbers matching car for sure. I welded in US Cartool subframe connectors and their full chassis stiffening kit in addition to welding the torsion bar crossmember solidly to the floor, thinning it out in cross section and reinforcing it with my own fabrication.

The shock towers on the late 60's A-Bodies are just hanging in the air with a few spot welds at the top to hold them to the inner fenders. I welded mine solidly to the inner fenders from the frame rail up, and have the under fender bracing welded in too. It makes the car feel WAY more solid on the road.

I painted my floor and trunk with that roll on bed liner for durability under the carpet. If you are interested in painting the floor and undercarriage body color, you sure would have to do the modifications before paint. I'll spray them all body color once I finally get the exterior paint done.
Click to expand...

am adding Gerst front K member and 4 link in rear (Dana 60). Should I look at getting level 1/2 frame stiffeners? Will also have a 8 pt roll cage.
 
HemiDenny said:
Just for discussion....the GV reduction is .78.....takes my 4:30s down to 3.35.
How much lower do you need in a hot rod?

I bought my second one second hand / but still in the box....delivered to my door for $1500. There are used ones out there if you want to save some bucks.
Click to expand...

Hey , how could .78 reduction ,take some thing down to .95 REDUCTION ---------------------------??
 
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