The total duration including lash ramps on my cam is 340 intake and 356 ex. At .050 it is 284 296. With .867 intake lift and .800 ex lift i need a lot of spring. If i don't set the lash within 5 degrees of the tdc 90, 180, and 270 marks it will be off by .001 to .006 depending on how far off i am. I use the 90 degree method setting 2 int and 8 ex at tdc, then 1 int and 4 ex at 270 etc. Follow the firing order each 90 degrees and you will have very accurate settings for hi spring pressure valvetrain. You will be able to spot problems early since anything moving more than .001 to .002 is a warning sign IF you are on those 90 degree points. Lash settings on the cam i have only allow for a .002 loose to .002 tight change due to ramp design.