To start with, we'll assume you've got an LA style timing cover/water pump on your Magnum stroker.
The difference in standard bypass hose fittings/angles is easily dealt with, and has been covered numerous times- start here ("Search" is your friend): Magnum engine swap | For A Bodies Only Mopar Forum
A Magnum style reverse-rotation water pump has a different bolt pattern, and will not even physically fit the LA timing cover.
Edelbrock makes a high flow LA pump that does not use cast-in hose barbs, which allows you to use different angled fittings to properly mate to the Air Gap. However, it's currently out of stock (What isn't right now?...) Edelbrock.com: Water Pump Chrysler 1969-85 318/ 360 in Satin Finish
Mr. Gasket (now part of the Holley mega corp.) does have their version in stock, also without cast-in fittings. Mr. Gasket 70340G Mr. Gasket High Flow Aluminum Water Pump - Cast Finish (holley.com)