Engine Build ?????
First before any work should be done the parts should all be cleaned and inspected very carefully. To make sure that the crank isn't bent and not out of round, they should also check the bores for the amount of taper in the cylinders. The rods should be checked for straightness and size, if all this pans out then the machining process can be started.
As for the inside mics. and a venier caliper they have there place and time to be used but they aren't the most inportant tools, as the venier can be off with regularity. Use these for reference only and not the final measurement. Good quality mics from starrett are a must. But are very expensive your shop should have these.
BJR Racing