Anyone know what this might be..

Ok.  So I finally made the purchase of a 1998 Ford Crown Victoria P71.  Drives pretty good and doesnt seem like anything is wrong, however I was going down an on ramp and decided to floor it.. As I floored it everything seemed to go fine until I heard a loud screech.. It sounded like this noise my friends truck made when we changed the fan belt on his truck... then the car jumped as if in a manual car and someone did an off shift if you know what i mean.. is this a sign that the trans is starting to go?  or could it just be doing this because the car has been sitting for a while.. other than that it seems pretty good.. the car seems very powerful as i seem to always have the rear wheels spinning.. actually thats another thing.. when i go to do a a standstill burnout only 1 wheel spins.. is this normal?

The tranny probably is going out on you if you are constantly burning the tires, these cars just simply werent made for it! when only one tire spins it means you have a posi rear end, an LSD (limited slip differential) would spin both.

1/Your burning up your right rear tire (lift your foot)2/your crown has not got a posi or traction lock .It is normal to spin on only 1 tire usually the right.

a posi will spin both tires not one