Soooo, As usual I got a couple questions for you that are out of the box as for the pther posters---------What oil do you have in the engine? What assy lube did you use and where? Rings, cylinder walls, bearings, camshaft components?


Since you have said that the ports looked same as others-------probably not a intake gasket-----

Now-as a matter of reality--------your heads need a complete set of new guides and valves, common on engines of the FE era ( 60,70s ers all brands) and there isn't a shop anywhere on this planet that will do that for $350-------

If you are running syn oil and/or used some dopie new stuff on the rings, you have glased the walls and will never get it broken in-------

If you still had it together , you could rev the engine while dusting Bonami powder over the carb and it possible would have helped.

Too many internet mechs these days will pussy around with a new build (most improperly done) and not create enough internal positive pressure sealing across the ring pack to put enough ring pressure on the wall to properly lap the ring edge to create the seal.

A breakin drive around where the engine is put under full throttle pressure ( but not into the top levels of rpm) will assist in a good breakin.

When asked how I breakin in my stuff I usually with a smile say that I adjust the valves, make sure it'll start and go to the starting line and set another track record------its worked for me for 70 years(considering starting at 5 years old)