Chip for blown 331???

[jonnyk]

A dyno tuned chip isn't going to help you if the chip burner doesn't know what he's doing. A mail order chip is a guess. A TwEECer is great if you know what you're doing, and have some way to measure A/F ratio.
If you can find someone that's good locally, go for a dyno tuned chip. If not, I would recommend a TwEECer and either dyno tune it with a wideband, or look into adding a wideband to your car.