Cylinders running too hot

I have a 408 stroker with an Indy mod man intake with the 3x2 carb plate on it. Bored .30 over with scat forged crank and Keith black flat top pistons. Mopar purple cam with .508/.508 lift. Edelbrock rpm performer heads with Hughes engines bigmouth porting. Center carb has 68 jets outboard carbs have promax carb billet jet plates with 88 jets in them. Anybody have any idea why cylinders 3 and 4 are running at 500 degrees on the header? Here are my header temps at idle after 2 or 3 minutes. Cylinder with temp.
1 200+deg
2 200+ deg
3 500 deg
4 500 deg
5 400 deg
6 400 deg
7 200+ deg
8 200+ deg
Anybody have any idea why the center cylinders are running so hot?