I am beginning to build another 350. This time, since I have a well equipped machine shop in my garage, I am doing the block prep myself. I have a couple of questions. Most of the published advice says to open the main bearing feeds to 5/16" on numbers 2, 3 and 4. Does anybody know why not 5? Some folks recommend using the TAperformance grooved number one cam bearing as well as bridging the lifter galleys at the rear of the block. Others say bridging the galleys should not be part of any performance rebuild. Does anybody know what the ins and outs are around this issue? Just for info, I set the block upside down on my Bridgeport mill to open up the main bearing feeds as well as the suction line hole. I nodded the head 18 1/2 degrees and that seemed to work well for both.