I have a 95 mustang that was originally a v6. Now I have a 5.0 in it and I want to convert the instrument cluster over to 150mph. Is it simply plug and play or is there more to it? Will this make the tach more accurate and the speedometer? Right now the speedometer reads 5mph too fast even after the Ford Dealership got there hands on it. The tach seems to be reading higher the engine sounds to be revving to. I would greatly appreciate the help

 

If your new motor is an EFI motor and you have done a complete swap (that is the computer and harness and all) then it should be plug and play. Your speedo being off now is prob not because of the engine swap but your tach may be. Need more details