funny noise

I am about to buy a 93 XJ country 4.0 aw4 231. I have dealt with a lot of xjs but this one is making a noise that sounds like... the best way to describe it is as if one of the flywheel bolts is loose and is hitting something with every rotation. The noise speeds up as the rpms increase. I havent taken the trash plate off the front of the bellhousing yet (will do that tonight). And its not the normal knocking that the 4.0 does. I know that noise all too well and this is not it, this is really loud. Has anyone ever heard of anything like this?

had the very same thing happen to me. thot it was bearing or something, turned out 2 of torque converter bolts were smackin' tthe block,replaced w/ 2 from a yard trip w/ some blue loctite and never had a problem since, been 3 years.