Water pump hose block-off

I've tapped the heater hose nipple successfully but never tried doing the bypass hose. Since it's aluminum you and not real heavy wall you just gotta take it easy when tapping. Aluminum likes to gum up taps so back it out just as soon as it starts getting tight and clear the tap threads and go at it again until you get it deep enough. Before I tapped and installed a pipe plug on the heater hose nipple I tried a set of those rubber hose block off's from NAPA and in less than 10 miles 1 blew out. Never trust them again.