A suggestion from Vintage Air was to use a water neck riser like this
https://www.summitracing.com/parts/v...BoC4XMQAvD_BwE
The bypass was something he questioned also. He said mostly big blocks need it but not small blocks.
There is a member named sweetk30 on the site that had mentioned needing the bypass to solve some issues he was having...here are the comments
"dont forget L31 vortec has no bypass hole port in the block so you need to do a bypass hose like a bbc uses . or you can get bubbling / girggling / coolant smell as it pushes up in to the over flow tank .
and the port might be in the block to the water jacket area but the head surface to head hole is not there . this is why you need a bypass hose . the true vortec L31 installs from gm the water pump has a hose and the intake has the spot for it "
And here is a link to the thread where it came up. My first attempt at getting the water pump and intake sorted out.
I sure hope this gets cleared up soon so I can get this stuff installed.
https://67-72chevytrucks.com/vboard/...d.php?t=811209