While working on the plane yesterday, I pulled some of the tape off the intake manifold area and discovered two little holes in the primary injector area, on either side of the bolt hole. They go into the primary injector area, and there are matching holes on the stock manifold, that look like they are connected to a manifold vacuum line.

Question: Has anyone used these -- or did you just block them off with the manifold gasket. I speculate that they are used to help give a puff of air on the injection cycle.

I think that is exactly right, Bill; better distribution of fuel spray/vapor.

My custom manifold blocks them off, as do most alternative manifolds.  Apparently they are not an issue for the rpms we are interested in.

Al