Lets see if we can get two birds with one stone here...
Im running my 90 xj, which is actually running the 4.0 6 out of a 89 comanche....anyways, ive had smoke coming out of the breather cap on top of the valve cover, but not enough to where its effected my oil level. No over heating, no lifter clicks or nothing, and its only when its at OT.

As for the belt, I just got a new one (last one shredded after neglecting to tighten it for too long...), and ive kept my eye on it, but it STILL squeals, but only when 1) it JUST started, 2) i go above 800 rpm, 3) once its got up to OT. if its not one of those three, then it sounds fine. but ive kept tightening and tightening, and i keep thinking its fine, untill while going down the road i start hearing it.
any help would be VERY appreciated by the neighbors

 

Clean and inspect the tube that runs from the rear valve cover grommet to the intake manifold. Check to see if the intake manifold nipple is all crudded up.

 

I looked at both ends of that line and its clean, the breather cap seems to be breathing....not sure what else to look at

 

There is no brreather cap. It's an oil filler cap and it's not supposed to breathe.