402 stocker engine

[Henrys Toy]

Originally Posted by Jrh5220

Well BP I had worked in a engine shop for several years, I just thought may be someone else had ran into the same problem.

Good morning to all,
Something Alan said struck me, as we might be looking at this all wrong. What kind of an oil pump are you using? The reason I ask is it possible that the oil pump in pumping a great deal of oil up to the rocker arms and flooding the valve cover area and I'm going to guess that you aren't using a valve stem seals on the exhaust valves. If you have excess oil in the valve covers and you don't have exhaust valve seals, while the engine is running the puffing through the breathers could be caused by oil blown back from the exhaust stems.
Take a valve cover off and remove the distributor and install an oil pump priming tool. Put a 1/2" drill on it and spin it up, then observe the amount of oil being pushed through the pushrods and out the rocker arms. You might be surprised how much oil can flow through there. I have a Schumann pump in my engine and it does a VERY Good job of oiling the engine. When I first primed my engine the oil shot out the rockers like I never saw before. I had to restrict the oil flow and got that under control.
I'm not saying that's your problem, but lets assume just for a moment that with the pistons and rings being new and good quality and you've had this engine apart a couple of times, maybe its not the rings or pistons or even the cylinder sleeves. but we're looking in the wrong place.
I still believe you should put this engine on a dyno at this point and put this situation to rest. On a dyno you'll also know just how much Power this puppy makes. The best of luck on you're search here, keep us informed as to what your conclusion is.

Respectfully,
Henry Kunz 1534 H/SA