A 1974 Duster - My 2nd one, 41 years later!
i was going to post this yesterday, i don't know why i didn't...........i have a 5 inch tach mounted under the dash, under the radio in my ride. i raced the car several times and don't have to look at the tach because the shift light (which alex has) almost blinds you at shift points........so there is no need to look at the tach while racing......i also do not have a speedometer in the car and use the tach to determine mph while city driving/highway driving and have never had an issue where i didn't feel like i could glance at the tach to see how fast i was going because i would be compromising safety........just sayin'........it's your car put it where u want it.
here's a pic.
higgs