Does shooting a somewhat lightweight arrow, say 425g out of 55# draw hurt a older bow? Do you need to be at or more than 10g per #? As always your advise in appreciated, thanks.

You are not even at 8 gr per # so I don't think I'd do it.  The 10 gr per # figure gives you the right combination of speed and stability for older bows so I try to follow the tried and true with the old stuff.

Nobody knows that answer for sure.......personally I like 11-12 gpp out of any bow; 8 probably would not hurt the bow-new or old.