i have a 91 camaro rs vert it was 305tbi and i installed 350 tpi. i also changed speedo to 145 out of a 92. now the mph isnt workin.does ne1 know if it has nething todo with the tbi to tpi conversion(buffer box)or if it has to do with being a 92 speedo???i have been searchin older posts and havent really found exactly what i am lookin 4......all i found is that a 305tbi has a buffer box and a 350tpi doesnt have a buffer box....is this true???and do i need to remove it??

 

bump???

 

The instrument clusters are more or less plug and play. So it has nothing to do with the fact that the speedo is from a 1992 car. 1991 and 1992 cars are essentially the same. The problem lies somewhere else.

 

buffer box??