just noticed that the shift lever will travel from park to D but not further than that, there is still two positions available. I used a little bit of force but did not want to break anyhting. pulled the bottom cover from the steering column but there seems to be nothing binding or snagging the lever. I'm thinking the cable may be stuck or something. anybody ever had this issue? Another thing I noticed is this transmission (i'm assuming a 4l60e) shifts great while cruising but at WOT it will shift out of first prematurley and sort of over rev before engaging 2nd, almost like a slip if you will. Same as when trying to engage passing gear while cruising and giving it throttle so it can down shift, very sloppy slippy. any thoughts. my 4.3 vortec is the non TBI model.

 

sounds like you have a broken shift cable casing ..i had the same problem on my 96. replaced the shift cable assembly and all was good again ......approx. $100 at napa .