I have a Mercruiser 120 hp 1983. I just installed a new gas tank. The fittings on the tank are 1/4" pipe outlet. The fitting on the fuel pump are 3/8" pipe with a barb fitting of 3/8" for hose. I need to buy an anti siphon fitting for the tank with a 1/4" pipe with a 3/8" hose barb. Will the constriction at the tank cause a problem. I would like to run a 3/8" line from the tank to the fuel tank and yes I will be installing a water separator and filter.