Follow the vacuum line from firewall, next to brake master cylinder down to vacuum pump. Remove hose from right there and see if it’s pulling vacuum. If not, fix the vacuum pump. As well as the ol girl was running, I cannot imagine a blow by issue from anywhere else.
White smoke on start and rough sounds like fuel lines at back of block in drivers side. 3/8 and 5/16 about 2’ long each. I remember resealing the tappet cover, which requires removing injector pump. I cannot imagine me putting it back together without new lines, but I don’t remember specifically changing them either. I w