th350 electronic speedo??

[i_live_in_canada]

I just swapped a vortec 350/th350 combo in my 1990 Chevy and now I'm wondering how I can make my speedo work. I read something about swapping the speedo sender on the 700r4 into the th350 tail housing. but im not sure if that will work. anyone done this before??

thanks, Tim

[speedygonzales]

I wasn't aware the 700R4 was ever electronic. I thought by that time it had switch to the 4L60 label. None the less here are some search results I got for you.

http://www.oldengine.org/unfaq/leadfoot/th350in.htm

https://www.youtube.com/watch?v=Hy7hPPIXk5M

https://www.youtube.com/watch?v=WTngjBKes00

Also Monster transmissions has good technical links

https://www.monstertransmission.com/...nfo_ep_42.html

[Texasdeere]

I believe you can just swap the mechanical speedo sender from the tailshaft housing with your old digital one from the 700R4.

My 1988 C3500 TH400 had a digital sender in the tailshaft. I am pretty sure I swapped it over to my built 700R4 when I changed out the transmissions.

[Stormin08]

my 89 700r4 is electronic speedo output at the tail shaft...i just deleted all the factory ECM and wires, i am going the other way and installing a mechanical drive (sensor conversion). along with vacuum control rather than electronic.