The chamber with those boots has been discontinued. Honda doesn't offer just the boots so I guess the '78 is out. I'd rather not install sepparate K&N filters on this bike. Cost being one factor, water getting in the engine if the bike gets caught outside in the rain is another. I ride to work on occasion. Predicting rain in Kansas will never be absalute. I wonder if a guy could fabricate some small hose, like that used on turbocharger tubing, would work. Maybe cut the lip off the intakes where they pass through the chamber so a good seal would be assured around the hose. Clutching at straws here.....