NOS Mercury 40ci Block - NEW. Block assembly # 349. All blocks are measured with a Sunnen Bore Gauge System. STD bore is 2.441. Exact bore sizes compared to 2.441 are as follows:
#1 TDC - straight side of cyl: - 0005
Bottom - straight side of cyl: - 0005
TDC - port side of cyl: -001
Bottom - port side of cyl: -001
#2 TDC - straight side of cyl: -0005
Bottom - straight side of cyl: -0005
TDC - port side of cyl: -001
Bottom - port side of cyl: -001
#3 TDC- straight side of cyl: -0005
Bottom - straight side of cyl: -0005+
TDC - port side of cyl: -001
Bottom - port side of cyl: -001
#4 TDC- straight side of cyl: -001
Bottom- straight side of cyl: -001
TDC- port side of cyl: -001
Bottom- port side of cyl: -0005