I don't know about startup but if it happens when you raise the revs after idling for a while, that is the classic symptom of valve seals. Is there any chance that too much oil is flooding the rocker area, say from a broken feed tube?


1951 GMC 1 Ton Flatbed -- It is finally on the road and what a great time I have driving it!
1951 1 Ton Completed


My Chevy Master 4 Door is on the Road!