Quote:
Originally Posted by busterwivell
Has anyone figured out the issue with these? I have an HEI in my 402, and the tach is way off. I know I've got a 4:10 rear end, but the tach reading would indicate about a 7:50. Can they be calibrated? A friend suggests it needs a filter?
|
First off, are you sure you don't have a 6 cylinder tach instead of a V8? There should be an ink stamp on the back of the tach that tells. You might be able to see it with a mirror and a good light.
There are also part numbers for each. This was posted by Member Ray Mcavoy:
GM #6468321 is for the 6cyl gas engine tach.
GM #6468228 is for the 8cyl gas engine tach (except medium duty trucks with transistor ignition).
GM #6468320 is for the 8cyl gas engine tach with transistor ignition.
All of the stock ones I have used have been pretty acurate with the HEI.
LockDoc