Thanks fellas for coming back together on this one. I didn't specify my classification because I wasn't asking a rules question, but rather I was trying to just glean experience related to car behavior/performance. I'm running in C/GMS at Wilmington, OH. "Streamlining" is pretty well unlimited forward of the cowl in this class, per the rulebook. My car passed tech in May and set a new class record without protest, and I talked with the inspector about the issue of covering the grill, so I should be ok with the rules committee. I will run with one eye on the temp gauge and bring a hole-saw as recommended. If any of you guys have tried this before: blocking the radiator (but still running electric fans), then running full-throttle/full-load for 30 seconds of track and then a couple of minutes of return track driving, I'd love to hear your story. It's just something I've never done, that's all. That's all I was hoping for-a good story or two from somebody who's "been there" and lived to tell the story.