"Well Yar this I the first I’ve heard of this in all the posts about making the change."
Don,
I didn't know either until I built a complete PCV system and found that there was no vacuum in the crankcase with the engine creating 21 inches of vacuum idling. So I attached my AC service vacuum pump and turned it on and heard the noise of air rushing into the crankcase through the back of the engine. Checking further I found that the engine has a huge oil drain-back passage between the pan and the slinger on the back of the crankshaft. Prior to that I thought that the only opening to outside air at the back of the crankshaft was the rear main bearing clearance. Live and learn, huh?
I'm sorry to be a bearer of bad news Don but unless a rear main seal is added the PCV system won't work.
My '36 restored pickup pickup has been running since 1976 with the draft tube system so I guess it'll stay like that forever.
