Your supposed to tighten them down in stages 40, 70 and 80. The 4.2 has always been 80 as far as I can remember, I believe the 4.0 changed sometime over the years from 70 to 80 final torque.
Don't confuse main bearing caps, with connecting rod cap nut and bolt which is 60-70 depending on the nut size 9/16" or 5/8".
Did you plasti gage your connecting rod bearings, that's often where the rattle is and often the first bearings to go.