I have a 351w with a c4 trans. truck starts in any gear..what do i do to fix

 

You need to wire in a neutral safety switch. Some are on the side of the trans betwen the linkage and housing.

 

found the switch..3 wires hanging there ..witch wire to where. thank you

 

I'll look thru my manual and see if it gives the color codes. Only 3 wires? I figured 4. 2 for the start circuit ans 2 for the back-up lights.
The easiest way is with an ohm meter. Pick one wire and check the other 2 while in park. If you have continuity between 2, then put the shifter in R or Drive. If you lose continuity, then these 2 are the neutral safety wires.

 

thank you..soon as weather cools a little I'll go out and check/fix.