those numbers given for cam timing are .050 numbers.

intake opens 6 degrees BTDC, closes 38 after. 6+180+38=224.

intake installed centerline is 106 ATDC, or 74 BBDC.

1/2 of 224 is 112. 112-74= 38. to figure out advertised ICP, just take 1/2 of 274, (137) and subtract 74 137-74=63.

can't really build compression until the valve is closed, so IMHO the .006 ICP is a better indicator than the .050 ICP + 15 degrees....

for instance, just in hydraulic roller lobe profiles,
look here: http://bulletcams.com/Masters/HRlobes.htm

for 226@.050 lobes, bullet has 10 different profiles with .006 duration ranging from 276 to 293, which assuming the lobes are symmetrical, would mean a .006" intake close point 8.5 degrees later for the 293 over the 276....these lobes also have an 18 degree range (133 to 151) of .2" lift duration.