904 won't come out of park

Put engine & tranny back in car, having trouble with tranny coming out of park & going into gear. Sometime it works others we have to rock the car to get in to release. We adjusted the shifter cable a number of times and can't seem to get it any better.:banghead: Were thinking the cable may be stretched out, should we try a new cable? Can I even get a cable any where? It's a floor consule in 65 Dart, wonderfull cable & linkage set up. I'll check back in morning, thanks everyone