help with 98 xj classis rear noise

I have just purchased a 98 cherokee classic from a family member,44 rear and a 2 inch block lift in the back.

the noise is when i accelerate somewhat hard.only on take off,If i take off slow it doesnt do it.It almost sounds like its a muffler rattle or somthing like that,I did have all new cat/muffler replaced and i got under it and it all seems nice and tight,No rubbing or anything.

checked the rear axle and its not coming from there either.

the noise to me sounds kind of like a door stopper,The ones you mount on your moulding in your house to keep the door from smacking the wall

boooingg

i have a similar noise, personally i think mine is the transfer case linkage, it leaks pretty bad and when i pull the 4wd lever a tiny bit to snug the linkage up it stops for a length of time

dont know about the noise but if you read enough on here block lifts are bad they cause the rear leaves to sag badly and will invert your springs eventually

that lift will eventually be gone,I personally wont use them,How ever i cant take them out since im running stock rubicon wheels and tires