Hello again. I addition to my valve to guide clearance question another one pops up. In searching the technical section I found the valve guide install procedure with a photo showing exhaust guides counterbore up and intake down. I bought new valves and guides from Andy Bernbaum Parts and since for me anything that can go wrong will i got 4 extra guides. They came in a open package of 4, a sealed package of 6 and a second sealed package of 6. These where all put in a baggy with a single part number. I opened the first bag of 6 and they where the same as my extra 4 with a nice long lead on one end and sharp shoulder about 5/8" down from the end on the other. They where not counterbored, they where countersunk about 1/16 of an inch at about 45 degrees, like you would do for a flathead screw. I did not even consider installing any upside down since that sharp shoulder looked like a problem waiting to happen. I installed 10 and then opened the last package of 6, installed my last two then noticed they where lacking the counter sunk inside. So I wondered if these two bags where supposed to be 6 exhaust and 6 intake and my 4 extras where just random. A quick call to the Andy Bernbaum I was told all there guides have the same part # and come from the same bin. Any difference would either be a design change or a vender change and all their guides install the same direction with the lead going down. I would like to hear from the forum on this one. Thanks from the new member Flat Jack

Many aftermarket bearings have been made that way, but it's not correct. It will restrict oil flow to the bearing. You'll need to take a file or Dremel tool with appropriate attachment and open up the hole in the bearing to match the oblong shape of the hole in the engine block.