There are a pair of 5/16" posts threaded into the intake between the center and rear carbs. Hoses attach to this fitting. The fitting points to the passenger side. Another 3/8" hose runs to the PCV valve in the valley pan. The original "F" fittings were plastic. Heat and age have taken their toll and most originals are long gone. We do now offer the Nylon in the shopping cart for $16.00 This piece is metal, painted a silver color. Also have a kit on the page to replace the rubber hose going to the F-fitting and PVC valve.