IMHO, it's silly to check end-float and then decide to reduce it by shimming the drive side alone (or timing side alone). If you really want to shim, then here's the procedure as I see it:
1) Install the bearings you will use with no shims.
2) Install the crank with rods and torque the cases - no cam needed right now.
3) Install the cylinders with no pistons, don't have to be torqued just well tightened.
3) Push the crank all the way to the drive side and move the rods all the way to the drive side
4) Measure the distance from each of the small ends to the drive side cylinder bore, average the two measurements and record.
5) Push the crank all the way to the timing side and move the rods all the way to the timing
6) Measure the distance from each of the small ends to the timing side cylinder bore, average the two measurements and record.
7) Using those two measurements and checking end float, move the crank to the center and the rods to the center of the journals and repeat until the rods are centered in the bores and centered in the big ends.
8) From centered measure the end float in each direction.
9) Subtract 1/2 of you desired end float from each of those two numbers - now you know the required thickness of the shims on each side.
No, for a street bike I don't bother, and I don't shim. One customer insisted on a blueprinted bottom end for his 73 850 - I did as above. He specified .008 endplay cold and once steps 1) and 2) were done, he had .022". In the end, everything was fully centered with .004" on the drive side and .010" on the timing side to achieve .008" endplay. To me, this proves that just shimming the drive side is bad.
At a minimum, if you insist on shimming, split it in half and shim both sides!