I quit using the 2.375 Mopar rod journal size stroker cranks about ten years ago, maybe you should to The smaller I.D. diameter rod bearings don't travel as far per revolution as the larger ones do Another plus in my mind is the lighter recripocating weight and less stress at the same RPM from the lighter rods As far as tight rod bearing clearances like your using I would open them up to at least .0030 or bigger, same thing on the mains, try .0035 or larger When the same components fail time after time there is usually a reason for it, the hard part is figuring out what is causing it What brand and part number rod bearings are you using?What type of rods. aluminum or steel? How about oil pressure hot at the upper RPM and weight of oil BTW, what RPM are you using as the shift RPM in each gear and at the finish line? #6 rod journal gets its oil from #4 main bearing, if your using the stock type internal oiling to the rocker shafts the oil for those comes out of the #4 main also