ARP Headbolt replacement questions and performance advice needed...

I already have a HKS MHG on my 87' Supra T and want to get ARP headbolts to be safe.

Planning to run 15 psi at the track and 12-13 psi all the time. Things buying to complete upgrade are: E-manage main unit and Profec E-01 boost controller, fuel pump(Walbro), upgraded intercooler that fits factory piping(Spearco?), F/R sway bars, suspension later and strut braces, also cross-drilled and slotted F/R rotors, racing seats?. Already have MHG, 3000 pipe, RC 550cc injectors, Lexus v-8 AFM, Apexi power intake, Custom 3 inch turbo back exhaust, apexi twin chamber blow off valve, a very subtle kaminari body kit, stage 3 clutch kevlar mix. konig rims (18" want 17" and diff. style but konig). Any other stock parts need replacing, to be safe, for hopefully 350 hp at 15 psi at track and around 320's at 12-13 psi daily, this is all after tuning it at a dyno.

Back to the headbolts...what are the torgue specifications for ARP headbolts? Tighten all gradaualy correct? Existing MHG should be fine, right? Any other hints or comments about this would be great, thanks.

74lbs is what everyone says i do 80 on arp bolts but do what u like ive had no problems