Loud Clunking Noise

A little history on Duster:
I got the car about 4 years ago. The man I got the car from gave me a list of parts he had replace. The paper work I got from him said replaced from Mancini's Racing Inc. was a MRE-875489 ( 2006 for the price of $950.00 ) if you look up the number it was for the complete centersection Mancini 489 8 3/4 355 gear... todays new price is $1395.00 ( Wow ). Over the last few yrs it has been fine but i did notice it making a few weird noises last year. The breaks are new as well last year when i put the new 360 motor in. The Axels are Yukon which are new also. I am now sure on Green Bearing seeing there is no sheet telling me what he installed I could ask him but was unable to talk to him last night. I have never checked the lube, I should have when I put everthing back together last yr but didnt. What is hard to understand is the tightness of the rear end when both wheels are off the ground and no drive shaft installed It is very hard to turn the tires weird feeling. It doesnt make the noise all the time, it seems the tighter the turn the more it clunks..... IT doesnt do it all the time and never going straight. I can add the sure grip stuff but wanted to talk more about it also.