Whatever pump that you use, make sure that the bypass hole is drilled.
The Wieand is not. Don't panic though. It only needs a 1/4" hole.
You want the bypass open on a Pantera. On a Mustang, maybe not.
Just curious why you want the bypass open on a Pantera water pump? I've had the Weiand on my Pantera for 10 years without issue. Warmup might have the temp needle climb and fall a couple of times, but engine gets to temp pretty quickly and then runs cool, regardless of the outside temps.