Re: 390 rod knock noise, have oil pan off
Yes use the new bearings for measuring-
yes youcan reuse the the same bearing as long as the bearings have the exact thickness, there may be slight variences-
Your crank looks to be in good shape as per your pictures, I would use a polish strap on the crank to clean it up and then after plasti gauging install the new bearings.
I would pull the main caps as well, your already there....just remember #5 cap has the needle seals in them, they will more than likely break or get damaged removing the cap. you'll need to get a new set for that cap. If you can't get the set you can use a bead of right stuff in the groove and make sure you install the cap dead on straight. I have done this before....not really recomended, but it does work.