When working with the original style castle nuts and cotter pins I tighten them as much as possible with a 1/2" drive breaker bar. I also coat the shaft of the perch (where it goes through the axle) with silver anti-seize to make disassembly easier on the next guy.
On a side note, it always amazes me how many cars I see that don't have the cotter pins installed with original perches and castle nuts. It's kind of a critical part that you don't want to come loose.