273 rocker arm adjustment
actually the shaft will have (3) holes (3 and 6 and 9 o'clock), 6 o'clock is already there (on the bottom) & you are adding 3 & 9 o'clock plus plugging the already there OE side in the shaft hole that is clocked wrong & the rocker will have (2) (3 & 9 o'clock) ,you are drilling the 3 o'clock hole & the inner 9 o'clock is already there & you are capping the top rocker hole & capping the outer 9 o'clock rocker hole when you are done drilling thru the already there 9 o'clock inner rocker hole into/thru the shaft.