just bought my car and the speedo seems to be off just by a little margine... did the 305 TPI 88 trans am gta originally come with the 140 MPH cluster or the 120. i think the previous owner might have switched it. anyway just let me know thanks in advance.

 

my 86 iroc TPI 305 came with a 140mph speedo not much help now i have pnned it a couple times with the new engine

 

My 88 HAD the 305, but i believe it was carb. Anywho its got the 140mph in it. Come to think of it I've got an extra cluster around here somewhere...

 

well maybe my car needs to be calibrated. the guy did mention somethin about the car have a posi rear*not sure of ratio.... and also installed a shift kit??? would these things change the speedo off coarse a little bit? thanks guys

 

I changed.. Engine, tranny, driveshaft, and the rear end is a 1989 GTA, to convert to 4 wheel discs

Still got the cable driven speedo.. still pretty accurate

My engine is modded to all she will hold pretty much, and tranny has a stage 2 shift kit