Well if the arm is longer after 0 it will add what ever it can add over the stock ratio.. I am keeping it simple as the longer arm deal comes down to testing back to back to see if you get any changes. I would start with intake first, and see what you get..
Here is but one test bike 2009 107 R&R cast heads stage V HO ( 315+ CFM ) comp ratio 10.8 zilla HPI 55 crane 296
stock rocker 123.88 hp 121.13 tq VS 1.7 S&S rocker 124.04 hp 121.67 tq this was back to back on the dyno. Pull tank swap rockers re adjust the push rods and go again.. To me that is a flat out draw and nothing came from it , yes we also tried a few other cams and the results where pretty much the same.
In some case's you might get it to work , but until you do a back to back you really cannot make the statement one way or the other.. I tell guys leave the stock one's in there for a street driven bike..
You have a 15,1 comp ratio drag bike a well thats a new test ..