Contact DLS. I have been running that one for 3 years. It uses the external bypass. Make sure you get the correct -12 o-ring fitting from XRP unless you want to notch your frame. I forget the part number but it's in there online catalog. It is a low profile fitting.
With 30 years of Buick oiling system experience, this pump incorporates the latest design features, and are machined to closer tolerances than any pump on the market.:smile: