Just got finished moding my CIA tube myself , was able to find the stuff localy ,but stumbled across this web site in my quest for the 4" to 31/2" -90 . Ogburn's Truck Parts in Fort Worth has all the same stuff , just a little higher in price.
Ask for Chris Steward , 817-332-1511,800-792-8916 , www.ogburns.com.