Removed the intake manifold from the engine. Cut the manifold at the entrance to the slight bend before the "T". Fabricated an insert similar to a washer to go in the place the tube was cut. The washer insert has a sloped surface on the inlet side and a straight sharp edge on the exit side. The purpose was to introduce fuel on the inside wall of the tube back into the air stream.
Re-installed the manifold with the insert washer. Did another test run, but the insert did not improve the mixture distribution other than at WOT. Probably need to design a new manifold.
