My 72 cutlass originally had just the clock. I know where the wires go but some say because its HEI I need something to work with the coil. Please advise. Thanks!

 

No, there is a tach terminal next to the coil + terminal, just buy the connector that plugs in to the HEI.

 

In 1974, I got two HEI distributors from Mike Barnard of Olds engineering and tested them in my 66 W30. He said that the HEI gives a square wave pulse and my factory "sidewinder" tach needed a sine wave pulse, so se sent a tach adapter also. The setup worked fine. More recently (about 2007), I put an MSD box into the Rund car and using a new Auto Meter tach, did not need any adapter, although I got an MSD tach adapter just in case.

 

Thanks

 

My car has a Sun Super Tach III and works fine with the tach connected directly to the TACH terminal on the distributor as oldcutlass posted above. I can't imagine there being a need for an adapter with a typical aftermarket tachometer.