Quote: I am looking at my 440Source 4.250" crank (RB) and ... It appears the 5-6 journal is drilled larger (0.79" dia) and not as deep as the others which are all the way through and about 0.71" dia. The larger bit/tooling for the 5-6 requires it to be at a slightly larger angle than 7-8 and the amount of metal removed may be the same.
BG, what are the dia of the lightening holes on your low deck (B) crank for comparison?
I am wondering if the B and RB are drilled differently, or it could be a production change (different years, mine is 2007).
