Im not trying to sell you my rods - just trying to explain that you are going to get in all sorts of shit of you use those ones with the 155.5 c/c
CP 8.2:1 are a flat top that come flush with the deck.
CP 9:0.1 are a domed piston. The flat of the piston come flush to the deck with a small dome in the centre.
CP RB30ET pistons have a small dish with valve reliefs.
To get 8.5:1 your prob best to use the 8.2:1 and skim the head - but obviously work backwards and cc everything first to calculate how much to take off the head.