Gear Vendors Overdrive


Mar 11, 2021
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Has anyone got any pictures of a Gear Vendors overdrive in a C body? How much did you modify the floor pan and crossmember? What sort of angle did the engine and trans end up at and did you lose any ground clearance?

I've got a '68 Plymouth Suburban that is getting a 440/727/GV. I’ve had to trim the crossmember to fit around the overdrive and I’m going to have to modify the tunnel to the trans up to the stock location. Not sure whether I can make the clearance by hammering the tunnel out or if it’s better to cut a some out and reweld a new section back in.
Might be better to cut/weld/re-brace the floorpan tunnel as to time and effort. Just ensure the body is supported securely when you do that, for good measusre.
Looking at your picture, I now understand why it is said you will have to modify the tunnel.
Yeah, it certainly won’t fit right without some modification. I think cutting and rewelding is the most likely option.
Would the short adapter put it in a place requiring less clearancing?
Yeah, it certainly won’t fit right without some modification. I think cutting and rewelding is the most likely option.

Below is a link to a thread on a 1967 C-body wagon where @Mike66Chryslers says Gear Vendors requires no mods to cross member and mod to trans tunnel involves BFH. Job may be easier than you think!

Overdrive options
Might be a different adaptor or crossmember but there's no way the stock crossmember was going to or on this one.
Thanks. No experience with Gear Vendors OD. Too much money for cars that are driven very few miles.

Value judgment for me. Thought the thread might help. Best of Luck!
Looks like there are shorty, 8”, 15” and 18” adaptors for the torqueflite. Mine came with one that is 13.5” so I guess that is considered the 15”. I think the 18” would be the best fit as it would hang the overdrive behind the crossmember, up under the seat where there's more room in the tunnel. It still looks like some clearancing would be needed but not as much.
Anyway, it's mocked up in position now, just need to brace the crossmember and recreate part of the tunnel.
That would be a heavy truck or motorhome output housing (and related shaft/parts) but be aware that some have provisions on top for a big pin that mounts/grounds a driveline parking brake.

Don't know if they all have that, but the one I have in storage does. I don't know if the brake can be removed, and pin-boss ground off, to make a short-shaft version that is compatible.

OOPS - the pin-boss doesn't matter as that housing isn't used. But the question on the output shaft is still valid. But seeing as how GV originally supplied this overdrive to the motorhome industry, they should have all the answers.

My shorty transmission just got a bit more attractive to me!
Club cabs had the non RV brake short housing because they use a carrier bearing and 2part drive shaft