Correct gear ratio

[Brandon]

You could try your 3.89s with a Gear Vendors overdrive. That has an 0.78:1 ratio, and makes a big difference in cruising rpms (a 22% drop.)

I have that setup in my 4-speed KR (3.50 rear) and love it on the highway.  But you still keep the regular non-overdrive performance everywhere else.

Pretty straightforward to install. You will need a shorter driveshaft, though.

Did you shorten your original driveshaft or get a new one made?  How do you control it with a stick?

You could do either, but I had a new one made. 

I have a Hurst t-handle shifter, with the button on the t-handle.  I put the control box in the glove compartment. It has red and green lights to indicate whether you are in O/D or not.  When up to the mph that I want O/D, I push in the clutch, push the button on the t-handle, let out the clutch and you're in O/D.  Simple.  There's also ways to split gears, 1st low, 1st high, and so on, but I never do that.  I just wanted reduced revs at highway speeds. Works great for me.  Check out their website for all the info.

I've used a GearVendors in 2 other cars and they work great, but those were both automatics.  Same purpose as you, not to split gears, but to reduce RPMs on the highway.  I wasn't sure how you'd do a clean install with a stick shift though.  With the automatic is goes on automatically, and I have a floor button (high beam style) to manually punch out if I want more speed.

I don't have a hurst handle, so I'd have to try and do something else creative...  Could go with a floor button, but would be great to have it on/near the stick.

[67 GT350]

I like that idea, but I went to the website and wow, got lost. Do you have a part number? I think that would be way cool with an automatic!

[Brandon]

To clarify, neither of the automatics I installed were in Shelby's. 

Best bet for a part # is to call them up.

[kjspeed]

I just built a C6 with a Gear Vendor OD for my 68 project. 49" from bellhousing to tail. She's a whopper!

[oldcanuck]

So if I am correctly reading between the lines here, my stock ratio in my '67 GT350 with an open 9", no air and 4 spd is 3.89 ?

Thanks in advance.......

[Bob Gaines]

So if I am correctly reading between the lines here, my stock ratio in my '67 GT350 with an open 9", no air and 4 spd is 3.89 ?

Thanks in advance.......

You are correct.