what brakes are on it now? skinny 1 3/4 A-body drums/shoes?

or the larger brake with 4" wbp?

this will depend on the flange offset on the axles. if it has the large offset for large brakes..

then yes,you can buy axles with large brake offset and 4.5 wbp and re-drill drums.

I used moser axles with large brake offset and 73 C-body shoes/drums/backing plates on my A-body 8 3/4