340 Ultrasonic Wall Measurement Sanity Check
The cast date I have written down is 6/18/67 so it's an early block.
My problem is with the interbore measurements with both our blocks- they are not possible in some locations. For example on your 360, #5-#7 depth B is .246 on one cyl and .247 on the other. Together that's. 0.493 worth of metal not including any core thickness. The maximum wall thickness between the bores on a 360 is 0.46 [= 4.46 (bore centers) -(2* 1/2* 4.00 bore diameter)]. That's reading .033 more metal than possible and no waterjack thickness. Same with my measurements- the sum total of the interbores come out to a number with little to no waterjack thickness possible. That leads me to think the probes are over estimating thickness a bit.
Rusty- with your probe are you getting something less than we are in the interbores?