Nodular S case or Nodular heavy duty case

[NorCal72]

Hi,

Im having Rons Rear end build my third member right now. Going with a True Trac 31 spline. My question is Nodular S case or Nodular heavy duty? And Steel or Aluminum pinion support? I need to let them know ASAP, any input is appreciated.

Looking at 6-700hp and a lot of cruising, minimal Auto X, road racing. I know I should have went S trac and 35 spline but I already have the axles and I don't plan on doing any 5k 1/4 mile launches on stickys. Im running this until I kill it.

Kevin