Having trouble with my Promatic 2 shifter... Ideas???

I ran that shifter in a few different vehicles, and i have never had an issue. You need to check the adjustment in park, Neutral and in 1st gear. This requires 2 people or you will be up and down under the car 3 times.
or 30 times

ps ;rev-limiters are great investments. as are decent valve springs. You can't beat seeing the tach needle coming down past 8000, after a botched shift, and "nothing bad happened",....... unless the rev-limiter was set to 7200.lol. No more worries.