RHS flow #'s

The RHS Heads take 2 size bolts or studs only. The bolts or studs outside the valve cover are standard. The ones under the valve cover are longer. The studs I used on the 410 RHS Heads are 5.75" long. Bolts used under the cover would most likely be a little shorter than that. I would guess at 5.50" long with the washer used. I have a set of ARP bolts for the RHS Heads in the garage but haven't measured them as of yet.