3.0 upgrade tach problem

[911novice]

just completed 2.7 to 3.0 swap. Everything is fine except that the tach doesn't work. Is this a wiring issue or do i need an sc tach?

[oh2fla1a]

Have you found an answer yet? I’m having the same problem..
Thanks

[CamB]

I dunno - I had an SC tach in my '75 and swapped it straight for a '74 tach - it worked fine.

[dd74]

My '74 tach works fine with my SC engine. Try putting the old tach back in, and if it works, leave it.

[Wayne 962]

Sounds like a wiring issue to me. Check the harness...

-Wayne

[flmont]

Hey Novice...How did you hook up the engine bay wiring for your 77'...and how did the ECU hook up go.???? Thanks Frank with the exact same upgrade ...