Look into SouthBend's HD-TZ clutch kit,
a sprung full-face kevlar disc and stage 1 pp rated at 300 ft-lbs.
I'm using this now on my b13 with u13det swap, t25, 370's, 4bar, 10psi
I'm very happy with it.
My previous Clutchnet clutch rated for 230 ft-lbs was almost twice as stiff but slipped at >8psi. The SouthBend's pedal feel is stock-like, but after an 800 mile break-in the kevlar disc becomes extremely grabby but still engages smoothly when I take it easy.
Part #KNS02