If I bought the 120mph indiglo gauges for my 110mph speedo, how off would they be, and how hard would it be to fix it? Thanks

 

Well, it would be a little off, and I really don't think you can fix it. You're much better off just finding a 150 speedo and getting the 150 overlay -> like I did.

------------------
1994 Black Z28 M6 T-Top 58k, Mods:
-Computer: LT1 Edit, AKM Elecronics Cable, TTS Datamaster
-Intake and Exhaust: Custom 4" PVC Cold Air Intake w/ K&N, !TB, Mac Hi-Flow Y-Pipe, Random Tech Hi-Flow Cat, Flowmaster American Thunder 2 Chamber, 3" Flowtech Cutout
-Transmission: B&M Ripper, ES Poly Tranny Mount, !CAGS
-Suspension/Wheels: Granatelli MS STB, LCA's, Mac Panhard Rod, Thick Spoke C5 Rims -18" all the way around Kuhmo ECTA Supra 712 275/35/ZR18's
-Cosmetic: SS Hood, 97+ Console, White Face/Indiglo Guages

 

What exactly do you mean 150mph speedo? The whole gauge cluster? If I did that would they still be off, and how hard is it to change the odometer? Thanks