Valve stem O rings

[JulioK]

Decided to replace the valve stem seals this weekend (never done it before). I've had the truck about 8 months and don't know much about its repair history. The engine had no valve seals and had crumbling O rings on the valve stems. My question is... Do I need to have the o Rings at all? I cleaned out the crumbling o rings and installed umbrella style seals but did not put in new o rings. I suppose I was not educated on the process thoroughly and thought that because the umbrellas did not come with o rings that they were not needed. Thx

Drove the truck about 30 miles and I'm pleased that it is not smoking when started now.