Rich, If it's a new repop, it doesn't require the sending unit. Summit, on line, gives you some of the details.

Frank/Rebop

Bristol, In ( by Elkhart) 

Rich, I think it depends on the model SW tach you have. I have one the I have had in numerous cars over the years that I have three sending units for 4, 6 and 8 cylinders. The one i have in my '55 has the sending unit internally and you change the number of cylinders with a switch.

Best to do your home work.

"The Master Cylinder"

Enjoying life at the beach in SOCAL

I am looking at SW Tachs on Ebay. Do they all need sending units or are some solo installed.

Thks,

Richard