Jock itch (tinea cruris) is a fungus, the same one that causes athlete's foot and scalp ringworm. The groin area is the perfect place for the fungi to grow and cause a fungal infection because it is moist, warm and dark.
The camshaft lift is the resultant net rise of the valve from its seat. The farther the valve rises from its seat the more airflow can be provided, which is generally more beneficial. Greater lift has some limitations.
In the case of the above Ford engines, the camshaft has sixteen lobes  one to control an intake valve and an exhaust valve for each of the eight cylinders. The engine block has sixteen small holes in the top (in between the cylinder banks) that fit lifters (also called tappets).