Gear Vendors Overdrive in a 1978 NYB

Kip Gardiner

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Hi all, there was a couple of comments on my gear vendors modifications to put a 4th gear in my NYB. The 440 is out of a 68 and has been rebuilt with 10:1 compression and the rear diff was swapped to a 3.21 sure grip so I wanted the gear vendors add-on to the stock transmission. When complete and running in 4th gear overdrive the rear end ratio went to 2.52. With 400 hp under the hood, that car scared the crap out me a few times. The link below will take you to my photobucket page.

OverDrive Trans by Kip Gardiner
 
I'd be interested in hearing details of the engine that fronts that GV. After paint, I'm looking at a rebuild of the engine in my Imperial and I'm interested in more power without sacrificing the character of the car.
 
Hi all, there was a couple of comments on my gear vendors modifications to put a 4th gear in my NYB. The 440 is out of a 68 and has been rebuilt with 10:1 compression and the rear diff was swapped to a 3.21 sure grip so I wanted the gear vendors add-on to the stock transmission. When complete and running in 4th gear overdrive the rear end ratio went to 2.52. With 400 hp under the hood, that car scared the crap out me a few times. The link below will take you to my photobucket page.

OverDrive Trans by Kip Gardiner
Thanks...but please just load the photos into here... PB sucks, all I get is ads.
 
Was there any modifications needed to the floor or structure of the car in any way?
 
No mods on the tunnel for the larger transmission tailshaft, the C-body was big enough but I did have to get the driveshaft shortened and ultimately just had a new driveshaft made.
 
If you are planning this Dave get a short shaft truck 727 out of a 4x4 with a divorced transfer case or a motorhome trans and get the "shorty" GV kit. It makes the overall length of the trans about 10" shorter which will improve your drive line angle.

Kevin
 
That's an awful lot of money. Looks like a 518 swap with a PATC control setup is a good alternative.

Not to say anything negative about this build. Just adding $3k on top of one of those guy's transmissions is pretty stout.
 
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Yes, $3,000 is a lot and it was more by the time you factor in drive shaft cost and time and trouble. I looked at a 518 alternative but they are not available for the RB 440 or B 400 engines. Small block LA engines got the 518 tranny.

The GV will change the final drive ratio by .78 or my 3.23 sure grip will drop to 2.51 and with a few mods to the 440, it will easily power that final drive ratio.

I don't do it anymore but I did try to find a top speed for that car a couple of times but without suspension mods and no speed rated tires I backed off the pedal at about 110 MPH and there was more there, lots more. I came to realize that my 78 NYB has the handling characteristics of a beached whale and I did not want to end up upside down in the ditch.

I bought a the 78 Salon with a an open differential 2.7 ratio and installed a 3.23 sure grip into it then installed the 4 point Reese receiver and the rest of addons including the triple core rad, power steering cooler so I could pull a 6,800 lb 30-foot wide body Airstream. I put the GV overdrive in it for the 99% of the time I wasn't pulling the Airstream. Below is a pic of my 78 NYB Salon car setup to pull the Airstream.
 
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Above is a pic of the Reese load leveling bars snapped up tight with sway control. Sway was a big concern with this setup as the NYB has no sway bars, all away control was done via the Reese hitch. The GV overdrive is obviously shut off when pulling this setup letting the 440 and 3.23 do their work. When not pulling the trailer just click the floor switch to turn on GV and the car is a missile.

That car does have the optional load leveling air suspension as well and the air shocks are functioning fine after I repaired it but it's the hitch that brings it up level. Part of the heavy trailer package for that car in 1978 included 1" torsion bars from the .991" standard torsion bars and they were acquired from a 75 Imperial which got 1" torsion bars standard. That Airstream tongue weight was 670 lb.
 
View attachment 134646 Above is a pic of the Reese load leveling bars snapped up tight with sway control. Sway was a big concern with this setup as the NYB has no sway bars, all away control was done via the Reese hitch. The GV overdrive is obviously shut off when pulling this setup letting the 440 and 3.23 do their work. When not pulling the trailer just click the floor switch to turn on GV and the car is a missile.

That car does have the optional load leveling air suspension as well and the air shocks are functioning fine after I repaired it but it's the hitch that brings it up level. Part of the heavy trailer package for that car in 1978 included 1" torsion bars from the .991" standard torsion bars and they were acquired from a 75 Imperial which got 1" torsion bars standard. That Airstream tongue weight was 670 lb.
Looks like a nice setup... and I love seeing your car working just as intended when built. My 76 NYB "parts car" was originally purchased to tow a big Airstream... The prior owners were kind enough to leave me an old picture of her in action from back when she was a newer car.
 
Another advantage of that setup for towing is being able to split gears.

If you're pulling a grade that is really working 3rd or drive hard but a downshift to 2nd is spinning the motor faster than you need to maintain your speed, 2nd in overdrive will put the RPM back 22% where the engine is still happy to maintain your speed.

Kevin
 
Yes Kevin, you know how the GV works and the GV will handle a GVW of 15,000 lb if my memory is correct.

I built it and used it a couple of years, gave the trailer to my daughter, they used it three years and it was recently sold and its in Quebec. Now I have the car still but not much to tow. It's a great tow car but the trailer brakes have to work properly. I have boats with no trailer brakes and the NYB gets going easily enough but stopping with no ABS is a white-knuckle event.
 
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I've switched from the Airstream to boats now. I have six Chrysler boats in various states of repair/disrepair and the pic above is at Moparfest 2014 in New Hamburg, Ontario. The boat is a 15-1/2' 1967 Chrysler Charger with a 105 hp Chrysler motor. The motor is also a 67 still running breaker point ignition.
 
Not sure I'm all that interested in who beats whom, but the main thing is that a dyno sheet doesn't tell me what was done to get there, which is my primary interest.

Dyno sheets don't pull 6500-lb trailers.
 
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