I'm constantly reading about the benefits of using spacer blocks on street rods between the manifold and carburetor, but I'm wondering how spacer thickness and design—open versus four-hole, for ...

Plenty of folks have penned articles on carburetor spacers. Some work; some don't. So when we came across a series of spacers from HVH (High Velocity Heads), we were, to say the least, a wee bit ...