If you installed the draft tubes the way Moroso shows on the link, how will the extra notch help?

Wouldn't the notch be seeing impact pressure?

Have you used a vacuum gage on the cranckcase to verifiy it worked better?

For best vacuum, I don't think the way Moroso shows is best. I've seen 3"hg negitive pressure in the crankcase from draft tubes, but they weren't installed like Moroso shows (and everyone does)

The exaust pulse blasts through the notch and out the angled end creating further venturi vacuum.

I have a few pics of one I installed on my old 66. send email address and I will send pics
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