FWIW -
I personally wouldn't have any car without a 5th or overdrive of some sort.
My GT6 originally didn't have an overdrive. I acquired a J type (saw it
sitting in a junk yard, bought the whole thing with tranny for $75) cleaned
it up, replaced the seals and installed it in the GT. Best improvement I
ever did to the car. I also reinstalled the 3.89 rear end ratio (which
came with the overdrive option over here) so I've got much better
acceleration than the old ratio of 3.27, but the same cruising speed rpm in
fifth as before the swap. Makes any trip over an hour MUCH more enjoyable.
The old Ford courier parts truck is the same, swapped out the old four
speed for a five and I'd never go back. In fact ALL my vehicles have
either a 5 speed or an overdrive and non originally had one. The never
ending project Spitfire has a single rail with overdrive waiting to be
installed in it SOMEDAY. As far as reliability, these things are built
like a truck. There is a vendor out in El Cajon Calif (suburb of San
Diego) called Gear Vendors that installs what amounts to basically a J type
overdrive unit onto the back of truck and motor homes. If it can handle
that kind of torque I don't think any of us has to worry about breaking
one. The same basic unit is used in the TR6, Stag, and various other
vehicles with much more HP and torque than even a hopped up Spit can
deliver and in almost 8 years (since I've installed mine) I've never had a
problem with my overdrive -
These are relatively simple devices, and if properly maintained, and not
abused, will outlast just about any major mechanical part on the car -
Barry Schwartz (San Diego) bschwart@pacbell.net
72 PI, V6 Spitfire (daily driver)
70 GT6+ (when I don't drive the Spit)
70 Spitfire (long term project)
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