TTI instructions to machine down the 90 degree oil filter adapter bolt head?

When installing the TTI 2 1/2" exhaust system on a '65 A body using factory stock exhaust manifolds the instructions I have state to cut one of the parking brake cable guides clean off and to also machine the head of the oil filter adapter bolt down to nothing. Are we doing that? And if not, what happens or doesn't happen? Maybe things have changed, my system was purchased about 10 years ago. Thank you.

http://www.ttiexhaust.com/Footnotes/pic-FN21FilterAdapterBolt.jpg