Blueprint 408 cooling system questions.

My 430 hp 367 ran hot right out of the gate.
After I tried everything, with no improvement, I tore the engine down and
had the cylinders honed another .0005,
then increased the ring gaps;
The engine was put together with a ring-gap factor of .0065.
I increased it to .008 factor
problem solved.

But I gotta tell you, cruising at 2500 or so, your engine will want CRUISE-Timing in the mid to hi 50s . This is in an effort to make the peak pressure occur around 25 to 28 degrees AFTER TDC, while the piston is still very high in the bore; so that the heat of combustion goes to pushing the piston down.
Whereas with your lazy timing the pressure is chasing after the descending piston. So you never get good pressure, for one, but more importantly the heat is going into the cylinder walls as the pistons uncover them. Then on the exhaust stroke, the gasses may not have finished burning yet, and the rising piston begins pushing them out into the headers where they finish burning in the ports and first few inches of the headers; instead of the headers "sucking" them out.

To figure out how much CRUISE-Timing your engine wants;
simply rev it up to cruise rpm and start pulling in timing, while simultaneously reducing the throttle opening to maintain cruise rpm. Just keep pulling and reducing until the engine rpm no longer rises with more timing. Now verify the rpm and read the balancer. Don't be surprised to see around 50* at 2500, or even more. Ok put the timing back.
What you have now, is a no-load optimum timing example at the chosen rpm. While cruising, this may have to be reduced say 3 degrees. Every engine is different .
So with your mechanical timing-only distributor putting out 34* at 4000/ 16 at idle; I'm guessing 25*@ 2500 is about half or less of what she wants.
And therein lies most of your problem.
I mentioned this on post #12, but that was a long time ago.
You will need a proper STREET distributor with as much vacuum-advance timing as you can get out of her, Ima thinking 22* with alloy heads. You will have to just buy whatever and modify the stops to get that much, as none was ever built for that.
And, of course, as already mentioned, you will have to bring the All-in timing in earlier; I suggest 32*/34 (alloy heads) at no later than 3400 rpm
The key is to get the A/F mixture all burned up and applying max pressure to the pistons at 25 to 28* AFTER TDC on the PowerStroke, so as to put all that pressure into the crank; and then sending the relatively cool spent gasses into the headers, instead of ;
heating up the cylinder walls..... with the water jackets right there....., and then sending the still burning gasses into the headers, thru the ports..