Shuddering under acceleration

[dannyca13]

I need some help. I've just completed a redtop swap into my s13. While test driving it i noticed a shudder that seems to be coming from the rear end while accelerating in 1st and 2nd at low rpm. I'm not sure if its wheel hop, tranny related or a boost leak. I'd appreciate any insight in how to diagnose/correct this problem.

On a funnier note my stock muffler decided to hop off my car last night. It said to hell with this and bailed after some loud scraping. I figure its the best way of saying buy a new exhaust.