I drove it about fifteen minutes getting into it. Is that still alright?
Yeah, sounds well within operating temps, using a hand held IR gun I'd get about 350-400 degrees F at idle full warm up in my Charger 440 on my stock HP exhaust manifolds, after a few hours cruising no more than 800-900 degrees F. but I have a Daytona, so they tend to run on the hot side easily because of the small grille opening...
Headers on the other hand tend to get up to 700 or so at warm up/idle and go upwards of 1200-1400 after some good run time depending on the tube size/coatings, the Chrome headers in my Challenger T/A get scary after a few hard runs, sometimes they're so hot and cherry red/orange it's scary, my IR only goes to 1650 F and I've pegged it a few times scanning them...
Mike