Making The Weak 7-1/4 Rear Axle Live... Kinda

I have a 7.25 in my 360/727 dart right now. I have driven it for a few years "babying" it and now that I have a 8.75 almost ready to drop in (no rush to swap it in at the moment) I have beaten the living hell out of it. I havent done any power braking but I tend to punch it at stop signs or while coming out of turns by my work when it's all empty on the weekends to whip out the rear. I regularly smoke the peg leg and she refuses to die. I was so scared to drive it at first and now I can't kill it...
My previous tires were really skinny (about 155mm wide) and my current tires (about 225mm wide) are really old and don't have much traction so I've never really made it "hook" either which I know helps the rear end live