Extending the vent via rubber hose and fuel filter works fine, just get it high enough that you will be above the highest water level you expect to encounter. Make sure you use hose that wont get rotted out by exposure to 90w.
Some axles have the little check valve that screws in. Take it out, screw a fitting in its place with a hose nipple on it and put the check valve in the end of the rubber hose. Dont forget to do the rear axle too.
Randy Rosetta KDØKWX TLCA #19351 2015 Rubicon Hard Rock & (2) 1970 Boss 302 Mustang's