Using a spin-on filter is a huge leap backwards in filtering ability, and unless you also install a 1/16" diameter restrictor in the return line you're going to destroy the engine with low oil pressure. How big are the lines from the engine to the filter and back to the engine? If they're small flexible lines, like less than 1/2" outside diameter, you've got a "bypass" filter that only runs part of the oil to the filter and dumps it back into the oil pan. The rest of the oil goes to lubricate the engine. Some late model 261's used a "full flow" filter with huge oil lines to and from the filter and flowed all the lubricating oil to the filter before supplying the engine with oil. That system used a tall, large-diameter canister with flexible lines with 1/2" pipe thread fittings, and a different routing of the oil inside the engine block.
DO NOT mess with the filter system until you fully understand how to make modifications properly. Right now, you've got a pretty simple leak problem. Don't destroy your engine in the process of trying to solve an annoying leak by making inappropriate modifications to a system that's worked well for over 70 years on millions of vehicles.
Jerry
