Note: Superior drivers with new style sump. Could you explain how you installed the fuel drain and plumbing under the Superior sump. There is a lot of exhaust pipe under there.
Is it OK to use auto hose? How did you terminate the hose?
I installed the sniffle valve then connected a piece of aluminum tube that exits near the exhaust. The tube is joined to the valve with a bit of heater hose and clamps. There is almost a 90 degree bend in the hose right where it connects to the sniffle valve to angle it backwards. It is very close to the exhaust so I wrapped the whole assy in firesleeve and I installed an exhaust heat shield on the exhaust pipe too. The firesleeve touched the heat shield.
I did similar to Andrew. However I had the orginal sump and therefore exhaust. When I changed to the new sump the exhaust was close to the sniffle valve. So I put a 45 degree adaptor on the bottom of the sump and this allowed me to angle the sniffle valve and pipe well clear of the exhaust. Then a piece of heater hose connecting to aluminum tube which goes to a P clip on the bottom of the firewall to allow any fuel to be dumped well clear.
Before you go to to much trouble, I have the same engine and I just took the sniffel valve off. Every time I turned off the engine I had a puddle of gas on the floor. I put the plug back in the sump and have had no problem since.