Have you verified that the pump functions correctly? A few years back I put a new fuel pump on my 383 and then couldn't figure out why I wasn't getting any fuel. Eventually we figured out that the pump was set up backwards, it pumped on the suction side and sucked on the discharge side. Took it back to the parts store for a replacement and the motor fired right up. Never would have believed it if I didn't experience it myself. Just another thing to check.