need to replace the tranny should i go rebuilt or used every one telling me(bone yards) that it must come from a 84 or 85 500 sel is this true?could it be the B-2 piston the car started moving like it was in neutral on take off then it would go third and forth were fine it was also making a rumbling noise during the take off fluid level looks a little high now the car wont move foward in d ,2,1 but rev works fine any tips help appriciated thanks