Anyone run the 8" (shorter) Gear Vendor setup?

[furious70]

Both the 8 and 18" are listed as for muscle cars, which works better?

 

[Kern Dog]

That depends on a few things.
My initial thought would be that the shorter version is for transmissions with the shorter extension housing and output shaft. MOST don't have that. I don't know that I have actually seen a short shaft 727 in person.
The shorter setup would be better for the drive shaft angle, especially in a shorter wheelbase car like an E body.
To convert a standard 727 to the short shaft, you need to disassemble the transmission.

 

[j-c-c-62]

That depends on a few things.
My initial thought would be that the shorter version is for transmissions with the shorter extension housing and output shaft. MOST don't have that. I don't know that I have actually seen a short shaft 727 in person.
The shorter setup would be better for the drive shaft angle, especially in a shorter wheelbase car like an E body.
To convert a standard 727 to the short shaft, you need to disassemble the transmission.

Since a longer version allows for a shorter DS, which inherently permits a higher limit on DS speed, which is the point of an OD in many cases, I would think that is a major factor in the decision. But that solution is offset in that in most cases the DS needs to be replaced or shortened, and that allows for a different DS design/material or larger diameter, both of which can up the DS limit if that is an issue.

 

[TorRed]

Talk to Gear Vendors. I asked the exact same question and they absolutely recommended the longer version. It's been a while but I believe they said it actually went in easier with no clearancing required other than a quarter sized 'dent' in one spot of the floor bottom. Again, if I remember correctly the shorter version did not go in as well.

 

[ckessel]

I have the mid length adaptor for mine on the 65. Want to say it's 15". They do list 3 possibilities in the catalog. For sure the main shaft needs to match which unit you choose to go with. When Pro Trans did my trans, since they are 904/727 Guru's, they had the correct shaft. I'm looking at doing something similar on the 67 wagon but want to verify what the actual length of the adapter unit is. Would like to have the OD unit as close as possible to the trans X. For me, I don't like having that heavy unit cantilevered out past the mount with no support. But thats just me. For size of OD unit reference, if a 5lb coffee can fits there at the end of your existing housing, you're good. I'm also checking into the 4L60 swap but want to see if it can be done on the non electronic one[ all hydraulic]. Less pudge in front of the X, better 1st gear and higher od ratio.

 

[furious70]

I've always wondered about it hanging way off the end.
And of course I found a used one so that's why I'm asking.

 

[ckessel]

The one I got out of a wrecking yard was used and off of a Ford RV. After exchanging the ext housing for what I needed[ they do that that for a fee] and having the OD unit inspected, didn't want to chance it since there was no history, I was within a few hundred bucks of just buying new. The OD unit was toast. They have them as an exchange too. I still have to buy the electronics as I didn't get them off the RV. All good now other than I'm still in build mode. Luckily GV was a 40 minute drive from where we lived at the time, so no freight involved.

 

[furious70]

Hmm... They talk like the od itself is indestructible

 

[ckessel]

I would imagine it depends on how it was treated. RV applications would probably be the worst due to loading and weight pulled. They say to stay under a certain GVW.

 

[Sixpactogo]

My 78 D150 came with the short shaft 727. I added a gear vendor to it many years ago. I can't remember how many inches it added or how much I had to shorten the drive shaft. (15" comes to mind) My truck had a two piece drive shaft and I remember I had to alter the angle at the hanger bearing because of the difference. I sold the truck in 2021. Last I spoke with the new owner, it is still doing it's duty. Here are a couple pics of the added length.
I think if you add a gear vendor to a car you may have to do some hammer work on the tunnel and possibly shim the pinion angle. They are strong though and I think they advertise them as being able to handle up to 1200 HP.

 

[junior340]

The one I got out of a wrecking yard was used and off of a Ford RV. After exchanging the ext housing for what I needed[ they do that that for a fee] and having the OD unit inspected, didn't want to chance it since there was no history, I was within a few hundred bucks of just buying new. The OD unit was toast. They have them as an exchange too. I still have to buy the electronics as I didn't get them off the RV. All good now other than I'm still in build mode. Luckily GV was a 40 minute drive from where we lived at the time, so no freight involved.

Sound like how most of my used part purchases end up haha

 

[OKDart]

Hmm... They talk like the od itself is indestructible

There's an episode of Roadkill where they install one. If I remember right, they explain that they can't be run under a certain speed or they can break. But they do sell an optional device that prevents that from happening.

 

[Kern Dog]

The one I had was an early version. the electronics were a bit clunky. The unit would often stay engaged even as I came to a stop. It was annoying. I had 4.10 gears, 3.19 in OD.