You would need a truly prodigious amount of 5/16" ID line to tame pretty much any brew. Even if you can't exchange it, the aggravation factor would be so high it'd be better to chuck it and just buy the right (3/16" ID) size line...
thanks day! I hate to waste 15 bucks but you are right...i think that I would wind up killing someone if my Southern Tier 2x IPA was coming out all foam...i'm such a dope :-(