What Neu for 5s in 8T?

2.5d...this will get you about 31,000 total rpms annd very good run times...I get about 30 mins of WOT with a 2.5d/6s 5000 set up .....so I would expect a little more......if you dont need that much runtime you could go with a 2d and that would give you less runtime but more speed