Overlooking something? Fuel Starvation

You did the right thing by setting the floats to 5/16". I saw in the book where it says it should be 7/16 but I had 2 I couldn't get to run right set that way. 5/16 worked much better. You mentioned your running the big canister filter. Is that the one Summit sells that takes either a 2.44" or 3.25" inch Fram canister filter and is rated at 90 gph? I ask because Don on FBO has a book out for tuning and he don't think much of it. He says they don't flow enough for a performance application. You might try one of Summit's billet inline filters. They flow 130 gph. Also checking the pickup like mentioned above is a good idea. I saw one that was plugged up once causing this problem.