i had a similar problem, however i was installing an autometer tach, there is an easier spot to catch tach signal. there is an ignition box on the firewall behind the air intake that u can catch it at that is where i got mine. i believe it was a white/black wire and it was the 2nd or 3rd pin from the top. i wouldnt know without looking at the car. jus figured i would toss that up.
