Hi, just finished installing a set of white face gauges with the 140 mph speedo (87-89 mustang GT kit) in my 89 stang (formerly 2.3 NA, now turbo). My question is that i noticed on the stang gauge it ranges from 0 - 6k rpm ... on the new gauge it goes from 0 - 7k rpm, redline on the tbird gauge is 5900, 5400 on the stang gauge. I looked at a few pics of 80's turbocoupes and noticed the tach matched what the new guage face reads. So i guess my question is this, since the tach is electronicly controlled (goes off of the distributor right?) is mine going to be correct with the new face on since the electronics are from a t-bird, or is there some kind of resistor in the cluster that adjusts it, and if it is not going to be correct how can i fix it.