I had put the old pump back on it already and it ran fine, cept the old pump, an Airtex, was leaking gas externally out the little hole underneath on the housing. Truck smelled like gas with it on. To make sure for myself that the new Bosch was bad, I put it back on to evaluate, and sure enough, it is sucking air and oil in through the engine. As you know oil gets pumped to the top end and is inside the valve cover and it keeps the pump eccentric on the cam lubricated. Air is inside through PCV circuit. I also observed air bubbles in the sight glass on the carb so I know that it was sucking air, and I think it was most likely through the same location; where the lever comes out into the engine to engage cam eccentric.
I went and bought another Airtex pump from AZ and the truck is all back to normal. I would have rather bought a Kyosan made in Japan but they are expensive and I didn't want to wait for it to arrive.
So I'm just chalking this one up to the Bosch being defective and sucking air/oil in from inside the valve cover. The Bosch was an $18 pump and that should have been a red flag not buy it. It's getting returned for refund.
Bosch mechanical fuel pumps; buy at your own risk.

Let us know how it goes with the new pump. I was also wondering the other night if perhaps your PCV was plugged.

Haven't seen a 22R fuel pump go for $18 in many moons!

Sorry I didn't see the last post. I went to A_Z_ and got another fuel pump and so far it's working great. Now it looks like I have a rear main seal leak that was supposed to have been fixed when I had the clutch replaced. Guess the old adage (if you want it done right , got to do it yourself) might apply.

Good Morning,

The stock carb is very pressure sensitive especially when they are old. I'm going to assume that you haven't rebuilt the carb lately and the float needle/seat is pretty worn. Your old pump was leaking through the diaphragm and down the weep hole, giving you a little less pressure to the carb. Change that out with a poorly made, brand new pump and the extra pressure pushes right past the float needle and down into the intake. Ultra-rich condition causes black smoke and plug fouling. Personally knowing what those pumps look like inside, it's impossible for the pump to be pulling oil from the head.

Glad its running better with the new pump, just felt like putting me 2 cents in <img src="/forums/images/graemlins/cheers.gif" alt="" />

On the rear main, was the seal just replaced or was a sleeve on the crank also installed? Those rear main leaks can be pretty pesky...