I wouldn't push for IQ testing solely based on reading one grade level ahead of grade but if there are other indicators, it couldn't hurt to see how it comes out. I don't think that the reading level is the strongest data you have to make your argument, though. I say that b/c many typical children read a grade or even a few grades above grade level but are not gifted. Your school is likely to have a good number of kids who read above grade level unless it is a lower performing school.
The types of things I'd bring up in asking for testing would include any test scores that indicate multiple years above grade level (although you aren't likely to have lots of test scores this early in the game), behavioral indicators, early milestones if they were fairly atypically early (say speaking in multi word phrases before age one), teachers who may have suggested testing, the Inview test results if the 95th percentile was the composite score, etc.
As far as waiting until 3rd grade, do they test everyone then? Also, is there any option for math enrichment before then if you feel that is an area where he really isn't being appropriately challenged now?
