[3 Deuce 64]

I pulled my 389 for a rebuild and replaced it with a 455 ( 77 K ) out of a cat that had been sitting 20 years the coolant was still a nice deep green in color. I ran the car for several hours before pulling the motor. No gages but no idiot lights came on for over heating.
What I have done; I pulled the 4 v intake and replaced it with a 65 tri power I had on the shelf. changed the later style timing cover to the early 64/65 style put on a rebuilt water pump ( that I have already replaced with the old one off my 389 because I found the veins on the rebuilt pump were 1/4 inch shorter the the original pump ) other than that everything is the same. the 389 ran between 180 -190 then 210 on a hot day in Parades . The 455 is running 210 -220 and as high as 230 . It actually vapor locked on me last week. Sunday I dove it to Syracuse which was about 110 miles one way . It hung on 220 most of the trip at high way speeds. Stopped by my friends garage yesterday he has a thermal tester with the red dot. checked different locations on the motor and it confirmed my gage though 47 years old is reading correctly. the only place the motor was reading differently was on the heat exchange cross over on the intake and that was reading the same as the exhaust manifolds over 400* .
One question I have is if I block off the cross over will that help take heat away from the top of the motor. either side of the cross over the temp is around 200*
What has me pulling my hair out is everything is the same except the long block. I have flushed the block but it didn't look crusty in the water jackets when I had the intake and timing cover off.
The other question is the intake didn't have a nice clean machine smooth surface there were some pits from sitting open for years . Nothing the gaskets would have a problem sealing but I am getting a surge jerk at lower RPMs under power ( Same dist out of the 389 ran fine ) If by chance I've got a vacuum leak around the intake would that because it may be running lean cause it to run hot . It idles at 600 -700 RPMs but has a sound like when the timing is too far advanced but it's not.
Other than that the motor runs fine yesterday I was doing about 15 mph ( frustrated ) just matted it she broke loose and smoked them into second and until I let off .

I'm not blowing out any coolant either the system is holding it so far anyway

To eliminate the intake I can pull the one off my 65 and switch it that runs fine