I don't see what is so bad about the current rule. It would be difficult to fit a complete aftermarket system in a standard PCM box with the adapter for the stock wiring harness. It can be done, but it would take a significant amount of time and money.

As for the vacuum line, I'll quote the saying around here. If it doesn't say you can, you can't.

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Bill
Planet 6 Racing
bill (at) planet6racing (dot) com