Hello,
When I take off in my 91 rs and give it a good amount of gas the rear end pops and feels like it drops. It only does it when I first take off and only if I punch it. Anyone know what this could be?

Mike

Check the transmission mount. Common for them to break from the pressure of the torque arm. Ever get a banging from what sounds like under the shifter? If so then the trans mount is bad.

Bob.

It wouldn't hurt to pull the rear end cover and look over your ring gear and spider gears. If the oil has shiny specs in it you know there is a problem.

When I broke 2-1/2 teeth off the ring gear in my old 84 Camaro a few years ago, it popped when I took off then howled at higher speeds. Not an uncommon problem with 10 bolt 7.5" rear ends.

may be nothing more serious than a u joint... Use jackstands, get under car and shake the driveshaft at all angles, at both joints..

GM had this problem with early 90 vehicles
Remove the drive shaft and clean and lube the inside of the transmission yolk. They have a special grease to use, I can get you the part number if needed. This should do it.
Good luck

GM had this problem with early 90 vehicles
Remove the drive shaft and clean and lube the inside of the transmission yolk. They have a special grease to use, I can get you the part number if needed. This should do it.
Good luck