Zionsville has conversion kits.
Technically yes, it is a federal offense. But then again, putting anything on an OBD II car that isn't OE (muffler, cats, O2 sensors) is also. Nobody gives a crap because there's no way they can enforce it. How would you proove the exaust on this car is OE and this one isn't.
If you've got inspections, or a state looking to do inspections, leave it OBD II, there's no way you'll pass with an OBD I conversion.
If you live in a state like where I live, where they don't give a shit and are more worried about kids doing drugs then people putting out an extra 2 particles per million of polution, go ahead and do it. Your car will be a beast.... even more so that it already is.
Kevin (President TBEA)
"WAAAAAAARRRRRIORS, come out to plaaaaay."