How do I get sucked into these things!

Ok, here is what I truly believe.

The stock suspension is a 4 link with a watts. The car can be driven with out the watts (been there done that).

The car can not be driven with the lower links gone. (Watts removed) So it has to be stock.

The car can not be driven with the upper links gone. (Watts removed) So it has to be stock.

So both of those need to be in place for the car to move and thus it is its suspension type, a 4 link.

The tri-link is basically turning the car into a different suspension type (a 3 link with a pan hard bar) with the air upper bushings installed. I do not believe this was the intent of the rule but others (of greater power than me) think that it is, so it is legal.

Roland