Final answer:
Tech B's statement is correct - the warpage on the cam side must be measured to determine if the head is usable.
Step-by-step explanation:
The question is focused on the inspection of an OHC cylinder head in a vehicle and the procedure for checking its warpage. In this case, Tech B's statement is correct. When inspecting an OHC (Overhead Cam) cylinder head, the warpage on the cam side must be measured to determine if the head is usable.
The thickness of the feeler gauge does not necessarily indicate whether the head needs to be resurfaced or not. If the warpage on the cam side exceeds the manufacturer's specified limits, then the head should be resurfaced. However, if the warpage is within acceptable limits, then the head can be reused without resurfacing.