[tm2173a]

I had my transmission go out on me recently, my friend was kind enough to go to the junk yard and pick up a used chevy transmission for me. the original was a turbo 350 with a 9" tail. The new one, which was sold to me as turbo 350 has a shorter tail and electronic sensor. The transmission is in and fits without changing the tail, but obviously the mechanical systems (speedo, vacuum lines) don't work with the new transmission. Is there a way to convert these systems so the transmission will shift at the correct rpm and I can read the speedo or should I take it back and demand a refund.

Thanks,

Novice mechanic

[SSedan64]

First determine exactly which Trans you have. The Vacuum Modulator connection should be in the same location.
TH350C has an electrical connector on the Driver side for Lockup clutch in the TC/Torque Converter.

The BOPC/BuickOldsPontiacCadillac TH350 use the large 2" Speedo Housing just like a TH400. It's the same size as the Electronic VSS. The Chevy TH350 uses a 7/8" Speedo Housing & Extension/Tail Housing with smaller hole. The Drive & Driven Gears don't interchange between the 2 sizes.

Gear etc.. Info.
Transmission Speedometer Gears
Speedometer Gear, Speedometer Gears, Ford, GM, Dodge 700R4

A Trans Shop should have the parts you need for the conversion, Gears, Gear Housing, Extension/Tail Housing or you can swap the complete Trans at the Yard you got it at.