confused with lug stud sizes. help

well got a 1969 dodge dart swinger 340.
has the 9 inch drums front and rear.
I want to change the all of the lug studs and lug nuts.
seems that there are a bunch of different sizes, im looking into having longer studs on the rear just in case. any recommendations?

its a 8 3/4 rear and its a one legged runner