Thanks for taking the time to chat! So I have heard varying reasons for my heating issue. Having the inlet/out let on the same side, is really a matter of path of least resistance. The flow is pressure based, so in theory, the water has less of a chance going through the complete radiator, being (64) being on the same side. I heard from an old time mechanic that they would/could heat up, (not overheat) in traffic when new. If you are correct, true I don't really want to update all my new parts. I do have a new 3 core radiator. (I can have my new radiator modified to have the inlet/outlet modified to the other side, for a reasonable amount). Good Clutch fan. I did fit a 65 cutlass radiator shroud that a company is making, that didn't change anything. Timing advance is working as it should. I do have an electronic ignition.
I have used only recreational fuel since the rebuild. But I didn't jet the carb for that fuel. I only drove the car about 20 miles before that, so I don't know if it had over heating issues. The Block/heads were boiled. It's bored to a 350 now. New internals, pistons, bearings, balanced, heads hardened seats, all new valve train, mild cam. Someone had just installed an Edelbrock intake & carb, which I reused. I do however have the exhaust manifolds that are bigger bore internally, maybe you have seen them (Thornton).
I did just install a electronic pusher 14" fan on the radiator, that made a big difference. When driving it will maintain 180-185. Sometimes, sitting in traffic, up to 190, then goes back down when moving. I have only driven it a couple of time when it was below 75 degrees. The real test could be today at almost 90. I When I shut the car off, the temperature will then still rise just sitting there, it goes up to 210-220, I don't know if I can do anything about that, is this a problem?
If you can help me figure it out that would be great. I have had it at 2 shops, both are engine builders and haven't had success in diagnosing the issue. I am happy to answer any questions that could help me along!