well if you want to safely make 275whp on your stock LS, have quick spool and not worry about blowing it up, i would take TheShodan's suggestion and look into the GT3251E. That turbo would meet your goals, have great response and just be a good turbo for your setup overall

 

Yeah, I'll be saving up for another turbo after I get this done, but the t3 60/63 is what I will use for the time being, and I want to push it as far as it will allow me to, while not creating too much heat.

Thanks for the input man