Wow!
Very enlightening, eye opening thread.
If ATR had 5 variants, how many variants did the KB headers have?
Now that i honestly do not know .. I never purchased a set of new KB's ever.. So cant comment on the evolution of them
A quick way to tell
KB from ATR is the flange.. Flat bottom that cant be bolted to a 14 bolt head are KB's.. Also the length of the drivers side collector is much longer on KB's
.. Also the merge quickly spells KB