Thanks for the advice.  On my appendix c test, SMAP 1, its 4 inch .338 wall, so we have to use a 3/32 root, hot pass, filler, and 3/32 or 1/8 cap.  I have delt with the thin out method, and as you said, blow through.  Im tempted to use the 3/32 land but more spacing.  My biggest problem is that my job title requires me to qualify each year with a 4 inch bell hole weld, and I might make 1 or 2 a year in the field.  The majority of my welds are simple fillet welds on punch tees for svc taps on gas mains.  I have made the determination that I have to practice my bell hole weld when ever I get a free chance.  Again thanks for the advice.