I am about to add a new pony to my collection. It has a locker rear in it. It is automatic and jerks alot in reverse and first until it gets going. Is that suppose to happen? He is telling me that they took it to a specialist and he said that the only way to stop that jerking thing is to change back to a stock rear. Am I being hosed?  It seems to me that the car was set up for 1/4 mile but never went. It has allum. drive shaft, shift kit and cobra manifolds oh and "racing cat converters (never heard of that either) Can someone let me know if this is normal? I have never been in a car with a locker rear.  

No, it should not act like that.  A locker is basically a pair of dog tooth gears (think long, square teeth) that lock together going straight ahead and separate in a turn.  A regular DL will probably make a clicking sound in a turn from the dog teeth jumping over each other.  The differential uses springs to tune the dog tooth separation in a turn.  When you straighten out they engage (often with sound) and lock both axles together.  I ran a Trac-Tech "soft locker" for a few years with zero issues on the street or track.  The soft locker uses a different set of separation springs than a regular DL, so it makes little or no noise.

Eaton Detroit Locker

Owner's Manual - refer to page 12 for checkout procedure

Don't make any decisions on what to do until you go through the checkout procedure.  If the differential action doesn't check out, then you'll have to service the unit or replace it.  A purchase price negotiation tool if nothing else.

PS - if it checks out and you keep it, a driving tip:  Respect the locker.  Before you stab the gas, sight down the hood because that's where you're going when the axles lock under power.  Be extra vigilant in wet weather because the lock/unlock on slick surfaces can be a bit unpredictable and can spook you a bit.  They are not inherently dangerous and are reliable and practically indestructible at the track.  I put about 2000 passes on mine before I switched to a spool.  Just make sure that after you come out of the burnout box you line up straight so the axles are locked correctly