hi my name is tony me and my father just recently purchased a 68 vette that had been sitting for 20yrs and rear wheels are froze upon getting it home we took off the wheels and brake calipers the rotors are not coming off are the parking brake pads engaged?  

If you can turn the rear rotor, they're not engaged, but if you can wiggle the rotor in and out a little, they're hung on the rust edge of the drum. If you can't wiggle the rotor, they are rusted to the spindles. Try something like pb blaster on the spindle flange.  

Well, this is a little late getting to you, but it's very likely that the rotors are still riveted to the spindles.  Look for 5 flat-head rivets spaced between the wheel studs on the outer flat of the rotor.  If these are still in place, Two men and a boy won't be able to pull these rotors off until you drill out the rivets.  These rivets held the rotors to the spindle during the assembly process of the trailing arms from the GM vendor way back in '68. If the wheels are indeed frozen ( won't turn no way no how ) , it's likely that the parking brake shoes are rusted, have swelled and are frozen to the inner drum portion of the rotors.  In this case, remove the rotors by first drilling the rivet heads from the outer surface and hammer them off.  It's not like you'll be using them again anyway!  After the rotors are off, you'll be able to remove all the rust, crap and corruption that used to be your parking brake assembly.  With a good punch, you can knock out the remaining pieces of rivet from the spindles.  It is likely that your trailing arm assemblies will need to be rebuilt, which will most likely require the services of a Corvette professional.  If you want to do it yourself, you'll first need to purchase about $200 worth of specialized tools, which by the way, you'll use just once.  This being the case, and if you still want to do it yourself, purchase complete trailing arm assemblies, ready for installation, from one of the Corvette vendors that advertise them. As you study the condition of your original trailing arms, you'll probably find that they are rusty (minimum), or more likely perforated with small holes in them.  This being the case, you'll definately want to replace them.  Buying the new assemblies will save you money in the long run, and get you on the road quicker.