Forrest,
When you say suction at the oil filler cap, you are sure it is suction & not the other way: pressure. Pressure would indicate worn rings, combustion pressure escaping past the rings.
I can only think of two things that would cause suction. Veeeery worn intake valve guides or the intake gaskets not sealing.
I alluded to this earlier: the gap between the intake & the heads. There is a fundamental difference between the alignment method of the max wedge intake & other intakes. Other intakes sit on the bathtub gasket & do NOT sit on the engine rails, front & back. If the heads or block have been machined, intake still sits on the gasket, although there might be problems aligning the bolt holes/port openings. But the gasket seals up ok.
The max wedge intake relies on it's underside to seal the engine rails, via the cork gasket. Heads or deck machined will reduce the gap for the cork gasket & using cork might prevent the main gaskets from sealing. This is one reason I recommended ditching the cork & using silicon to seal the gap.
So I would check these areas very carefully for gaps.
You said the float was hitting the baffle [ vertical tab ]. As I suggested earlier because you were using QJ needles, which I believe are shorter, this would explain this contact. The floats should not make contact if the correct n/s are used with a washer under the seat. A fix without buying new n/s is to add a washer [ or two ] under the seat if you have any.
