changing 85 mph speedo to 140

[88GT 5pt0]

What I did was took the instrument cluster to a local shop, they changed the it over to 140mph for $40 then I put reverse glow gauges on there that go up to 140mph, and colored the lightbulbs red with a sharpie (so the needles were red at night). Look in the phone book, mine had a section for speedometers in the yellow pages. However when I drove past one of those signs the cops set up that tells you your speed my speedo was 5mph off, not too bad. It looks great