A body - B body spindle swap

I will be running either the B or the M spindles on this duster. Already have the set off the satellite, plan to pull another set off a Diplomat and sell one or the other. The diplomat has the sliding calipers and I would prefer to use the pin on variety like off of the satellite. Are the M body spindles just a little lighter weight than the B spindles or is there any difference at all? Should be able to swap the caliper brackets, both are 10.98". Will have to keep looking for a set of the 11" caliper brackets.