I have a Romac 28oz on mine but yes there are different part numbers for our cars, difference could be how it is keyed on to the crank, diameter of the crank, etc etc.
As long as you order it with the 50oz it will fit/work. Balancers don't carry a certain year they can be used, they only go by counter weight i.e. 28/50/0 oz.
0241SA/50 is the part number for the steel inner/aluminum outer balancer and 0241/50 is the part number for the steel inner/steel outer. a 28oz. imbalance is for an older 302 and for 302 based strokers.