Remove the filter and see if the center hole in your mount has pipe threads in it. The simplest restrictor is simply an npt plug with a metering hole threaded directly into the mount. A 1/32" hole will result in no appreciable pressure loss and about 1 quart per minute of filtering. Line size won't matter as the metering hole will determine flowrate.

1952 1300 Canadian 1/2 ton restomod
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