70Matred442

I have a new to me 1970 442 with auto TH 400 trans and A/C and believe to be 3.23 gears. Does a one legger pass side burnout and was hoping for info/opinion on if it's a worn out posi/LSD or a non-posi. With the rear tires off the ground in neutral, when I spin either tire forward, the other tire won't spin at ALL. When I spin either tire in reverse, the other side tire will eventually spin forward.

Either tire spun any direction will turn the driveshaft and no weird noises so I'm pretty confident the axles are good.

Have not opened up the diff yet ( i know that's a sure way to tell.....) Diff has fluid up to the fill hole

Back of pass side axle tube stamped SC, front casting of diff is 40227

oldcutlass

It sounds like you have an open rear end.

70W-32

SC indicates a 3.08 open diff.

70Matred442

Thanks to 70W-32 and Oldcutlass for the responses. I did see in some research after my post that the SC code means open diff 3.08 gears. At least 3.08's will keep the RPM down on the Highway....