Marcus, make sure this is the problem before you spend a lot of time fixing it. I have a 81 Crossflow (80K miles) and experienced some thing similar. It was the plastic ball on the end of shifter, which had been eaten away. I still dont know why?
I had to replace this ball before I got good shifts again. I have pics if you want them. Send me an email address. series1@cfl.rr.com
Cheers,
