I know I have posted this before but here is my experience with an original hood tach as per the part number. This hood tach was on the car when I bought it in 2000.

1) When I purchased my car in 2000 the car had a dist from a 70s Pontiac with HEI. The hood tach was connected to it and the hood tach worked perfectly fine with HEI (no resistor) just the original wiring harness etc.

2) I then bought a stock points dist and installed a Pretronix II system and once again the hood tach worked perfectly (no resistor).

3) I am now running stock points in a stock dist and once again the same old hood tach works perfectly (no resistor) etc.

So all in all I can verify that the original hood tachs from Pontiac will work with all three systems as I have seen and done them on my car with no issues.

In addition, my friend down here has a GTO and he recently bought an aftermarket hood tach from Ames. We unplugged mine and tried the new one and it worked perfectly. We then installed it in his car which is using an HEI system and again, the after market hood tach worked perfectly.

So based on my own experience with an original & an aftermarket hood tach they interchanged with no issues, no resistor, no bouncing of the needles etc.