Just looking at your pics and a couple things jumped out at me. I read that you've already tossed the expansion tank so this may not matter but where the hose on the left side of the engine was connected is only used for temp sensors - can't see where the smaller hose is connected on the right side, but neither of those locations are high enough to properly bleed out air. They are more likely to disrupt coolant flow. These engines only had one heater hose outlet - on the rear of the passenger side head, the return was to the top tank of the rad, and drawing flow anywhere else could mess with things.
An expansion tank would probably work better if it was plumbed directly into the flow from the upper rad hose, kinda like the early 60's full size Fords.
Do you have a build thread on your car to satisfy our picture drooling needs??
Maybe I'm behind the 8 ball but it looks as though you're running the rad in the back?? If so, lots of other things could be contributing to your problem - flow restrictions, rad size, fan CFM, air flow, etc.
Pics, we need more pics, pleez... [P