I know several people with track cars and talked to them about gear break-in and they're reply was, We'll never see 500 miles on our vehicles.

I guess if you just plan on racing it at the track, it should be okay. But if you want longevity, probably good to have a break-in period.

 

I recommend changing it to get any possible shavings from the gears wearing in out of there. I did tdrumm's fluid after his first 500 miles and it was worth it considering what was on the magnet, alot of normal grey stuff GMCtrk reported that his fluid looked brand new after 500 miles, so I guess it depends on how the gears wear in. (tdrumm's gears had a perfect wear pattern btw)

 

If it's a strip only vehicle, you should probably consider using "Pro" or "Strip" gears. Most of the gear manufacturers have a line of strip use only gears that are forged from a different alloy that has a better ductile strength to survive hard launches, but would wear out quickly on the street. I don't think they require any special break-in (other than a couple of hard launches, probably!).

 

I will try and get 100 or so miles and go from there, if it breaks I always have the 2nd rear end.