New 94mm race piston, used 90mm and new short Carillo rod.Other way on ,100 stroke 90 bore so no issues with the studs. The flat top JE pistons have a flat circumferential squish band which matches to the one machined into the head, the ring pack is low enough to permit the piston skirt to come fractionally above the liner at tdc. The biggest bore useable without modified studs is 92mm. Ian's 94 bore race engine (1250cc) has modified studs but retains the original spacing.