in the case of a tachometer, i bought a 5" autometer tach from jeg's,
complete with a shift lite and the whole 9 yards.  i mounted it right next
to the instrument cluster.  i took a 3/16" drill bit and drilled two holes
right through the metal dashboard (didn't know it was metal before i was
doing this) anyway, the tach hooked right up, and the only tricky part was
getting the tach aimed properly.

Sudhir H. Desai                         1984 VW Vanagon 3.4 liter Chevy V-6
cdes@welchlink.welch.jhu.edu            1996 Subaru Outback 2.2 liter flat-4
sudhir_desai@geocities.com              1997 Jeep Cherokee 4.0 liter I-6

http://www.geocities.com/MotorCity/Speedway/1889