1970 Chevy Chevelle 4 speed shifter

is this a 3 speed or 4? If it's a muncie floor shifter they used to hang up and you need to go under the car and manually shift the transmission into nuetral and taht should straighten the shifter out. If it's a 3 speed look at the bottom of your steering column and see if there is a lot of slop in the shift levers. If there is then that will have to be rebuilt. The cure for the floor shifter is to get a hurst floor shift as it mounted to the transmission and not the body so when the motor torqued it wouldn't make the shifter bind.

If you put the car in gear, and then start it, does it go into gear?? If so, you have a clutch or pressure plate problem. You're not really giving us much to go on. hope we helped.
mickey-d