Ok me and my old man just purchased a 90 GT with a Vortec suprcharger on it. The previous owner had it tuned by someone in Maryland and he had drilled 2 small holes in the gas cap. I was told the reason for this was because due to the bigger fuel pump there wasn't enough air flow and thats why this was done. I personally have boosted cars and put bigger fuel pumps in and have never heard of this so my questions to all of you is: Is this a common thing??? Does anyone else have this done and could further explain???

Thanks,
Matt