@devonmikeyboy!To can support torque up for680Nm,(500lbf-ft), you can use a 2 disc sinter metal clutch for AP-Racing,or Alcon,orSachs,or....another RACING firmware with very best results.
Ex.Apracing:CP2125CRV ,orCP2125ACRV
184mm 2 Plate 'A' Ring Sintered Clutch
765Nm, (564 lb/ft)
For montage is not problems,the Set up height Max worn is 33,8 mm.
Anyhow,you must forget to use von this torques,a singel plate clutch!!!
I wait to say what power you have with big injectors,(PD),and VT7,without nos and propan.I think this is really interest for majority of us!
Best regards of all!!