Header temps
 

Is there a good temperature for headers?

SBC 355, pump gas, 671 blower.

I run about 675*F 2 inches out of the aluminum head at idle.

Is this high? My underhood temps seem hot.

Is the temp something I can use to tune idle timing and mixture?

Plugs look good after a WOT pass.

I have new XFI fuel injection and more adjustability that I am used to.