Fortunately, a little common sense and a few measurements with a dial caliper and a tape measure will help you to select the proper filter element. Bypass filters such as yours have a small hole drilled into the vertical standpipe in the center of the canister that controls oil flow. It's usually about 1/16 inch in diameter, and is located about 2/3 of the distance up the standpipe from the bottom of the canister. The proper element will have rubber grommets that are a very snug fit on the center pipe. Most canisters will have a spring built into the lid that holds the element bottomed out against the cross bar that's visible near the bottom of the can. As long as the element isn't too tall to allow the lid to be installed securely, the diameter of the element is pretty flexible. "Bigger is better" but it's not necessary for the element to fill the whole diameter of the can. The grommets MUST be a very snug fit to the center pipe, however. Oil enters the canister from the side port, flows through the filter media, and exits the canister from the bottom fitting after passing through the flow metering orfice. There's a lot of upward pressure exerted against the cover by the oil pressure, so use a new, properly-fitting gasket, and clamp the cover bolt down TIGHT! For instance- - - -a 4 inch diameter cover with engine oil pressure of 30 PSI has 377 pounds of upward push on it. Even a slightly loose cover bolt results in a nasty oil leak!
Jerry
