I setup my aluminum Indy Maxx with 0.0035" - 0.0038" on the mains with 400 journals. Number 4 main(0.0038") was not happy when I tore it down after about 100 passes and that journal had about 0.0008" runout. The rod bearings looked perfect and the rest of the mains(except the back half of #3) looked very good considering the number of passes and street miles I had on it. I talked to Molnar and they said 0.0038" might have been a bit too much with the expansion of the aluminum block and allowed the crank to whip killing the #4 main. Given Molar's good reputation, I couldn't argue his logic. This time around I went with a Callies crank and had the block line bored for 440 mains. It's clearanced at 0.003" on the mains now.