There is a anti siphon valve on / near the tank that could be bad.
Have your tech hook up scan tool to monitor fuel pressure while running. I still think it could be a tach problem - which feeds back to distributor and the distributor tells the ECM to reduce or shut off fuel.

BTW: PM me your address - I have some goodies for ya.

I've also had a soft spot in a fuel line once which causes it to collapse at higher RPMs, choking it for fuel, yet it will idle all day long without a problem, or run at pretty low RPMs. The choking was also sporadic when it happened. Nice thing was the fix was cheap and easy.

There is no anti siphon valve. I must've been removed. Weird but the pick up tube is welded inside the tank.......it can't be removed. I'm checking the tach and other electronics tomorrow.

Woo Hoo !!!!! Problem solved. Bad module in the distributor. Thanks to Ron Fulgenzi at First Mate Marine in Harrison Township.

Congrats!!!! Let the good times role now!!!!!!!!
Got mine out for the third time now on the ohio! Bring on summer!!!!!
Hope to see you out there!

Ah! When that happens the distributor is telling the ecu to shut down fuel supply.

Now get that puppy up over 65mph!