I spoke with Edelbrock and what the tech said was that if the block has the bypass port/hole on the passenger side directly under the mount hole for the pump (which mine does), and if the pump has a hole on the same spot then that is all the bypass thats needed on a small block thats running old school v style pulleys. I need to just double check if that hole in the water pump mount continues through the pump to allow for the flow.
This is the pump I put on and remember the hole but didnt check if it went completely through and didnt dead end somewhere.
https://shop.advanceautoparts.com/p/...m=water%20pump
So if it all checks out then he said just run the heater return line to the top of the pump and cap the port on the manifold.