So they're flared on both ends? Are they the "Precision Port" tubes?
Mine came with instructions ... basically took my port length (7"), subtracted 5" ... cut a piece of pipe 2" long, glued it together ... instructions said it would be 1" longer than your port length so I measured the final product and what would you know, it wound up being 8" //content.invisioncic.com/y282845/emoticons/tongue.gif.6130eb82179565f6db8d26d6001dcd24.gif