Oh wow, gonna follow build. Question, I just recently installed the same 4 into 1 Kerker on my 77' 550K, the stock exhaust collar doesn't fit on the Kerker header, does the Kerker header not require the collar? I've seen some other 4 into 1 exhaust with the flanges built on and those don't require the collar as the the fitment into the exhaust port has been enlarged.
Best,
JT