Fastback

I have a question for you, I know you hocked your factory rallye tach. What did you get for it? What did you stick in the hole? Mine works but in the upper rpm the 6000rpm scale sucks. I punch the car on the highway and the tachs useless. Not that I do much 6000rpm driveing but still. Had thoughts on stuffing a performance indicator from a barracuda in just for the hell of it and use the cash from the tach for some other goodies. Guess I'm bored