GV unit in a 66 B....anyone doing it?

[Cranky]

Looking for some info about the installation of one behind an 833. Downfalls vs upside etc. Not really wanting to modify the floor either.....

 

[Jerry Hall]

I've never done one, but I don't believe that the floor has to be modified. I worked on a 69 Charger that had one, but there were no issues with that, so I didn't look that closely.

 

[Kern Dog]

Since the 1966 is similar to the 1970, I can comment.
Mine fit fine. They tell you that you’ll need a dimple to the tunnel at 10:00 and 2:00. That is all. What can be a problem is the clearance for the speedometer drive. Without a 90 degree adapter, you have to cave in part of the floor so the cable isn’t in a bind. My 90 degree adapter broke and they claimed to not have any spares. Maybe they felt no obligation to sell since I bought my GV unit used. This was 2013. Maybe things have improved.
The unit did work though. The electronics have been improved from what I hear. Mine would stick in OD even when I came to a stop. I only wanted the unit for a fourth gear, not gear splitting.

 

[EdwardB]

Since the 1966 is similar to the 1970, I can comment.
Mine fit fine. They tell you that you’ll need a dimple to the tunnel at 10:00 and 2:00. That is all. What can be a problem is the clearance for the speedometer drive. Without a 90 degree adapter, you have to cave in part of the floor so the cable isn’t in a bind. My 90 degree adapter broke and they claimed to not have any spares. Maybe they felt no obligation to sell since I bought my GV unit used. This was 2013. Maybe things have improved.
The unit did work though. The electronics have been improved from what I hear. Mine would stick in OD even when I came to a stop. I only wanted the unit for a fourth gear, not gear splitting.

Mine did the same so I put a switch on the hot line from the battery. Only have to reset the brain every once in awhile. Incidence decreased with cleaning up the ground I can tell you.

 

[EdwardB]

Looking for some info about the installation of one behind an 833. Downfalls vs upside etc. Not really wanting to modify the floor either.....

I've been researching this for an A833 as well. I have a GV behind a Turbo 400 in a GM car. Love having the overdrive. Regarding the A833 I looked for UTube videos as I'm wondering what thei GV tail shaft replacement requires. Wondering if the GV tail shaft has a bushing for the output shaft as well. Wondering how short the driveshaft will need to be after GV tailshaft and OD unit is installed because it looks like it will need to be pretty short and the pinion angle might need to change. Might be time to talk to GV. They have been really helpful in the past

 

[diesel_lv]

66 is same as 67. I've got one on my '67 behind a 727. The 66 will most likely need the same massaging. I used an air chisel w a round smooth bit on it and gently massaged the areas that needed clearancing. Wasn't that big of an area, about 2" square and about 1/2" depth. The 833 may require it in a different area, but it's pretty easy to do.

 

[beanhead]

To dovetail onto what Kern mentioned about the speedometer...the new units do ship with a 90-degree adapter to alleviate the issues of the older kits HOWEVER we're talking 727s...not sure how that crosses over to the 833.

 

[Kern Dog]

The GV unit itself is the same for most models. What differs is the extension housing that replaces the stock tailshaft housing.

The speedometer is in the GV unit and sits at about a 9:30 position, aiming up a bit toward the side of the trans tunnel.

 

[BearDodge67]

Old post I know, but I told Cranky I'd post it for others.

I put one in my 67 when I converted to 4 speed in 2016. Excellent support from them during the installation and after the sale. It was fairly straightforward, I did have to bang out the floor where the top 2 bolts go. I did have to cut and flip the 3" tti H pipe because it interfered with the unit despite being told opposite. Other issue I had, apparently mine was first, was the tailshaft they supply is straight where it goes behid the gear, mine was beveled because the gear was beveled and it wouldn't fit. I sent them my tailshaft housing and they based the new design off that one. The only other issues I had was I had to shim the rear nose up a little to account for the longer length of the entire transmission now, and the control unit went south, there was an issue with the older models that was resolved in the updated ones. Because the H-pipe is so close to the unit, I wrapped the pipes in header wrap, and then found out it wasn't necessary (pictures show tie straps just for mockup). I'd do it again if I had a 4 spd in the car already, if I was converting, I'd get a 5/6 spd and use that. (Keisler was in their death throes when I started collecting parts, that's why I went that route).

 

[Cranky]

Old post I know, but I told Cranky I'd post it for others.

Hey, it's only about 3 months old. Old posts are usually much older lol and thanks for posting the info!

 

[BearDodge67]

And since you got a 833, you don't need the control box, you can wire it up so you can manually engage it. The only down side to this is the control box detects your speed and won't allow engagement under a certain speed (35mph I believe). Under that speed, the pump inside the unit doesn't generate enough pressure and will lead to premature wear, so the control unit automatically disengages it if you forget to disengage it yourself.

Also, you may see used GV units on CL or Ebay, they were actually designed for motorhomes I believe, so sometimes you'll see them for sale for around a grand. By time you buy the unit, then a refurbished tailhousing, the control module, speedo sensor, etc, you're almost at the cost of a new unit.

 

[Cranky]

And since you got a 833, you don't need the control box, you can wire it up so you can manually engage it. The only down side to this is the control box detects your speed and won't allow engagement under a certain speed (35mph I believe). Under that speed, the pump inside the unit doesn't generate enough pressure and will lead to premature wear, so the control unit automatically disengages it if you forget to disengage it yourself.

Also, you may see used GV units on CL or Ebay, they were actually designed for motorhomes I believe, so sometimes you'll see them for sale for around a grand. By time you buy the unit, then a refurbished tailhousing, the control module, speedo sensor, etc, you're almost at the cost of a new unit.

Not needing the control box is good to know. I've always been 'in tune' with my cars and always shut off the OD's in the 'modern' iron when I was running around 35 anyways....until the switch went out on the 95 Dakota for the second time so I just wired it where it was on all the time. It still shifts out when it gets slow so I never worried about replacing the factory switch which is pretty much extinct now and didn't bother with using a toggle switch. I'm not so hot with wiring since I'm shade blind.