assuming this is a top loader, you might have popped the shifter out of it's proper place.. It happened on an old GMC with a NP 420..but I was stuck in first gear. I ended up yanking, beating, spanking and screaming for about 2 hours before ole boy walks over, smacks the retainer off and pulls the shifter handle out of the cover.. we reset the handle and it was off to the races.. You also might have sprung the pressure plate or wore it out, hence the "pop".. does the clutch pedal feel any different?
