had motor job done on 79 shovelhead took for ride fine around town so went on hwy first time in 4th kept it on 65-70mph for 10mins when i pulled off hwy came to stop white smoke pouring out rear cylinder exhaust
lots of oil comming out exhaust ....is this prob head gasket or oil rings ?

 

Probably head gasket between oil return hole and bore, a leak down test will confirm it.

 

Were the cylinder head bolts re-torqued after initial heat soak?? For that matter, were the cylinder base nuts addressed as well??
Scott

 

ok pulled all apart,,,was head gasket blew out at down tube hole
put a fire ring gasket on now..will see what happens..hope was a just a flawed james gasket