TH400 swap
Melting Slicks
Joined: Jan 2014
Posts: 2,478
Likes: 254
From: Downers Grove Illinois
Safety Car
Joined: Oct 2007
Posts: 3,729
Likes: 267
From: Austin Texas
Corvette of the Year Winner 2017
2016 C3 of Year Finalist
Turbo 400 requires a electrical signal to control the Kickdown shift. Instead of a mechanical linkage.
for proper operation of T400 you will need a (switch / wide open throttle position),
to control passing gear kickdown.
for proper operation of T400 you will need a (switch / wide open throttle position),
to control passing gear kickdown.
Melting Slicks
Joined: Apr 2009
Posts: 2,632
Likes: 112
From: Great Plains Iowa
The TH400 was used in all of the high horsepower small blocks and big blocks because of it's higher torque rating. If you presently have a TH350 and put a lot of miles on it I'd strongly recommend changing over to a TH700R4 for it's 30% overdrive 4th gear. The TH700R4 can easily be built to handle 500+ ft/lbs of torque so it makes a great big block transmission.
Pro
Joined: May 2013
Posts: 672
Likes: 31
From: Rapid City South Dakota
I had a T400 in my '56 chevy with no electrical signal and the kickdown worked. Could be that it was an older trans....
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
My '72 has a 336 rear ratio, and so first glance some 18 years ago it was the 700, but in driving it, the car got maybe 1/2 way across in intersection, upshifted and bogged the engine, and I had FI on it even then......
the solution was a 200 4r no violent drop from 1st to 2nd.....smoother and still the same ~.70 overdrive....knocks 4000 rpm at 80 mph down to 2500 or so.....
AND you don't need to modify cross supports, driveshafts, etc.....
the solution was a 200 4r no violent drop from 1st to 2nd.....smoother and still the same ~.70 overdrive....knocks 4000 rpm at 80 mph down to 2500 or so.....
AND you don't need to modify cross supports, driveshafts, etc.....
Le Mans Master
Joined: May 2007
Posts: 5,009
Likes: 1,116
From: North tonawanda NY
hmm... there was no such switch on my 74 when I bought it? unless its installed behind the pedal somewhere? someone swapped the carb with an edelbrock right before I bought it.
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