I have bought the CCP part number 45045 for a long time. The larger 9/16-18 adapter included with the part number has recently been machined incorrectly and will not work with a stock 1/4" diameter line. They mistakenly machines it to work with 3/16" diameter brake line and will leak if using the stock 1/4" diameter brake line. You will need to call CCP directly to see if they have correctly it. From experience, it will be best to buy directly from CCP, as you may be waiting a long time if order through summit racing, jegs, etc. because the order will be shipped directly from CCP anyway.
The other alternative for a correct sized 9/16-18 IF adapter is from Brakequip. PN# BQ261 is a 3/8-24 IF Male to 9/16-18 IF Female. PN# BQ260 is the other line fitting with a 3/8-24 IF Male to 1/2-20 IF Female. This fitting (BQ260) had a design change that only mated it with a 1/4" brake line instead of a 3/16" diameter brake line. This actually will give you a nice brake line leak at the fitting. The design changed has been corrected to work with stock 3/16" diameter lines, but the fittings should not be available until next month
Hope this helps.