So i went from a 305 TPI to a 350 vortech carbed engine. i sold the engine wiring and computer with the old engine so basicly the only wiring inside my engine bay is comming from the driver side of the fire wall and its got the starter power wires, alternator, temp gauge ect. does the tach wire come through this bundle aswell or does it go through the computer? i talked to a MSD tech briefly and he had told me i need to get a aftermarket tac since i no longer have the computer but id rather not if i have an option. if i have to go with a new tach i might as well rip my entire dash out and rid my self of all the other wiring in the car minus the ignition lights and door controls.

 

The computer has nothing to do with the tach.

 

alright i ended up just removing my gauge cluster and tracking the wire back from the tach input. I plugged it into the msd box so hopefully all goes well i know the schematics for previous years show there being a tach filter to smooth out the gauge reaction but im pretty sure thats the board on the back of the tach so it should be fine now.