[runn141]

i have an 89 chevy c1500 with a factory turbo 400 with an electric speedometer. i want to swap in a 9 inch tailshaft 350. so i have a 700r4 tailshaft that measures 7 1/2 for me to use the existing electric speedometer from the 400. so my question is could i cut 1 1/2 off the the shaft? or should i try to find a longer yoke?

[mmerlinn]

Cutting your tailshaft will result in splines that are too short for any yoke.

A 700 tailshaft will not fit a 350. All of the splines are wrong on the shaft as well as all of the journals.

[runn141]

Originally Posted by mmerlinn

Cutting your tailshaft will result in splines that are too short for any yoke.

A 700 tailshaft will not fit a 350. All of the splines are wrong on the shaft as well as all of the journals.

well i just put one on it from a 700r4 and it fit. the output shaft sticks out 1 1/2 longer though.

[SSedan64]

The Tailhousing may bolt up but as Merlin said the Bushing journal, Speedo gear location/alignment etc... aren't in the correct location. Driveshaft spline engagment would be too short etc...........
TH400 Electr. Speed Sensor wont work in the TH350 or TH700R4.


This is for a 6" Tail TH350 >> http://www.transmissioncenter.net/_DSC1975.JPG

Part #350E2
http://www.transmissioncenter.net/sp...____va.htm#350

The TH700R4 & BOP TH350 use the same Speedo housing size & gears. 700R4 Electr. Sensor/Sender may fit BOP TH350 9"-Tailhousing.
BOP = BuickOldsPontiac.

[mmerlinn]

Originally Posted by runn141

well i just put one on it from a 700r4 and it fit. the output shaft sticks out 1 1/2 longer though.

Impossible. The front planet splines are different between the two shafts, both in diameter and in spline count. The snap ring holding the planets on are different sizes, too. That is just the front end of the tailshaft. The rest of the shaft is different, too, although the speedo journal is same size, but different location, and the output splines are same count and different location.