[Ol' Ron]

For floating bearings, you need the Bore diameter of the rod 2.220 for the 21A.
Bearing thickness times 2 for the bearing .108 x 2= .216
Crank throw 1.998 and add the crank to the bearings and you get 2.214 total clearance would be .006". Now when you mike the bearing thickness the .108 is very small .109/.110 is more likely. Then have the rods honed to 2.221"
I realize this is for the 21a rods, but it 's the same math for the 29A rods. I like to run these bearings alittle loose. Watch out for thr cranl fillit radius, it may drag on the bearing. Once the bearing is fit to the rod and crank scuff with #400 paper, wash in soap and water, akk assy lube and make sure the oil pressure is 40/50 lbs hot. With a good symthetic oil thay should last forever. I'm not sayint this is the only way to do it, it's the way I did it and it works. But the flathead is very forgiving and I'm sure others have good ways to do it as well.
Good luck.