+1 on the trans if you start putting power adders on it will only hold up for so long, as for the springs i have 4cyl springs front and rear they're a good cheap way to transfer weight. Only prob i have is real bad wheel hop when i do my burn out so a rolling burn out works best. I'd suggest changing the springs down the road its a real easy cheap fix. There's always a set for sale here.

As for the rear end you should upgrade to an 8.8 $hawn might still have his if not i know Steve b was selling one and Riverviewnative has one but needs some parts. They all go for about 100 bucks here on TR