I am restoring a WW2 CMP 15 cwt Ford truck in Australia equipped with the factory bypass filter mounted on the flathead engine and wish to use it. I have a 65 year old NOS filter element sample and do not want to use it due to its age and thought it would be easy to match it. Seems thought that all the newly manufactured filter elements for flathead engines Made by WIX, NAPA, and Purolator are much bigger diameter- just over 4 inches. The cannister it fits into is just 4-1/8" ID so there is very little side clearance if I use one of them. The original NOS element is 3-3/4" dia and 5-1/2" high giving good clearance all round. My questions then are: Do all Flathead ford filter cannisters have a 4-1/8" inside diameter? If so, doesn't it matter that there is only about 1/32" inch clearance using a modern filter element? Perhaps the military specified a different oil filter or Ford Canada used a smaller sized cannister on their V8's? Have eyestrain looking at filter websites trying to match the original dimensions so any advice will be greatly appreciated. Cheers!