I'm about to pull off the head to get new valve seals installed. Will I need to swap out to ARP head bolts to run 15 psi safely? I was also thinking of switching to a 85mm throttle body. This is on a b18c1 with 9:5:1, stock head, skunk mani and hondata. Will the 85 mm TB help much at this boost level or would my $$$ be better spent on head work? How strong are the stock head bolts?