OK, for what it is woth.--- What you are discribing is - a bad valve guide and/or a bad valve seal. The valve seat on #6 intake is probably just a little bad also. There is an easy way to remedy this. Remove your head and replace "all" valve seals but "do not" do a valve grind. Chaeck and see how all valves and valve seats look, if they appear pitted or carboned use a little valve grinding compound and a hand( a wooden handle with a suction cuo on both ends) valve grinder and smooth them out just a little, make sure you do this valve grinding primarily on #6 (as this is where the problem has been). Re-esemble and you are good to go again without big problems later on. Do not do a total valve grind unless you want to do a total rebuild, it increases the pressure on the rings and bearings to much in an old motor. If you don't fix this problem it will only get worse for you and your engine. The oil you are burning is because of the poor valve guide. The popping is because #6 intake is probably fouled and allowing gas to "after-fire" in the chamber. If you need more infomation on this please ask.
Oly in Oregon
Rest in Peace1945 GMC COE Victory Truck
1953 Willys CJ3B
1955 Chevy 1st series 3/4-ton
1958 WIFE Last series
Never say "Whoa" in a mud hole