I have a 55  272  with a problem of #8 cylinder pumping out enough oil to run out the manifold to exhaust flange   I have made a few changes and honestly dont know if either has affected the problem  and dont recall which came first.  I installed a 4 barrell set up with a t pot carb , at the same time removed the valley pan and built a baffle and hole to install a pcv  Again I dont really remember this issue before  but my memory is not the greatest . with the amount of oil involved I was sure there was a breach in the head gasket between # 8 and the oil return hole in the..  block , very close proximety . A very good friend and retired engine builder  has suggested  rings in that cylinder  , it had best compression of all 8.  but I didnt believe that much oil could be from rings on that one cylinder with good compression  Well I pulled the head off and much to my dismay found no breach in  head gasket  . my friend came over for a look and confirmed no gasket damage , all oil seals were in place and valve guides were good . So he pointed back to rings.  I just hate the job of pulling the pan  , ive done it before and have to jack the engine up and various other things .. I guess what I'm asking is does anyone have any great ideas as to  what  else   if anything could be going on or a similar situation   thanks in advance  Fred  at 76  its a bit harder than 20 years ago LOL