All rubber hoses will collapse/kink if bent tight enough. I was talking about straight runs of R9 hose with no tight bends. When you ask "the R9 hose will not collapse?" I am taking that question to explain that the R9 hose rubber compound is specifically formulated to withstand the ethanol and other aggressive fuel blends that our Mopars have to use today (unless there is an ethanol free gas station by you). If someone were to continue using the R7 hose with ethanol, then that hose would degrade inside and bits of the hose lining would start to break off (and if left alone long enough could cause collapse) and move into the hard line (possibly getting lodged in there) and/or travel into the carb and settling there causing more serious problems. When I changed my R7 hose to R9 hose, I changed all the rubber hose areas from the gas tank all the way to the carb. Don't change the hoses piecemeal, while you're doing it, change them all. There is a Quality Plus gas station in Maggie Valley, NC (next town over from me) that sells ethanol free 93 octane and that's where I fill up my 73 Swinger. But if I am travelling a distance to a car show and are forced to fill up at an ethanol blended gas station on the way back home, then I have the peace of mind that I can use the gas with ethanol and it won't degrade my rubber fuel hoses. I hope this info helps you...did you change the old standard hose clamps and upgrade to FI hose clamps also? My Dad always said "Do it right once and then you don't have to worry about it anymore"....words of wisdom that pertain to a lot of things in Life.
Take Care,
318MG
