Howdy, Bob Pet.... glad you got it setup. Meant to tell you (and EVERYONE else, sorry) that the Uniflow should NOT be used on these large-venturi carbs and big displacements. After I tested that setup on the Dream and the Excelleron, consulted with someone "in the know", we concluded to abandon the Uniflow on larger motors.

Just run a normally-vented tank, Bob, and she'll do fine.
The symptoms you describe are exactly why we decided to discontinue it.

I'm sorry I didn't get back here and tell everyone of our test results.