Help me please! 1994 Gt Transmission

[19Mach69]

I actually have a couple problems with my 1994 GT. I swap the AOD slushbox with to a 1994 T5 tranny. Now my speedometer is off by about 10%. Does anyone know about this? What fixes it? I haven't swapped the wiring or computer, the transmission works fine though.
Also, I have a slight rattle in the engine sometimes. It sounds like pre-ignition or maybe a chain rattling? Does anyone know about this? Help me out! Thanks a lot.

 

[Green 94 5.0]

the wrong speedo gear is in the tranny. what gears do you have out back?

 

[19Mach69]

I left everything stock. Just changed the transmission.

 

[bimmertech]

I left everything stock. Just changed the transmission.

there are two diff gear ratios installed stock and if you have 2.73's and the 5-speed came in a car with 3.08's then that would explain the difference. if you have 2.73's get the speedo gear for that. as far as rattling goes, it will take some time to get used to the new noises, so just give it some time to settle in before you go tearing down the engine.

 

[19Mach69]

Thanks for the advice. I will check it out.