Anyway you shake the dice, it takes air flow to keep them cool, you either have to fab a good shroud or get the electric fans for when your in slow traffic.
You can put a electric fan out front on a thermostat that only comes on at 200 if you want use it like a pusher fan when your in traffic lugging around.
I would never use fenderwell headers on a street car, they just plain look like ****, they are a cheap alternative to using the right parts, but its your car so do as you will. Thats my 2 cents.
How do you get heat in the winter if it doesnt go over 180 thats too cold for me I just made mine run warmer so I dont freeze this winter plus it helps burn condensation out of the oil when you do whort trips.