So I just installed the small cap version on my 65 GTO 389 4 speed no A/C car with 4:11 rear gears. Cam is an 068 grind running Tri-Power. Still need to do tuning with it but install went smooth and startup was quick and easy. Question for those who have used this distributor is running a factory tach. It’s off by approx 200 rpm. Worked correctly with points. I have the tach currently connected to the - neg side of coil just like when I was using points. I know it has something to do with how the factory rally gauge was manufactured and is not compatible with modern units. Question is can a Tach Adapter work to correct the issue? Something like this
https://www.allzim.com/store/tach-ad...e-adapter.html
Thanks for any help.