Thanks gents for all the info so far. Its given me some ideas to move forward with .
I'll get a cheap bore scope ordered up this weekend .
Then Plan is pull the carbs and ck backside of intake valves . I would think it it was a valve guide issue intake is most likely as they have vacuum on them. Exhaust is on the push side
I just ordered new plug tubes from Summit ,,,,,
The plug tubes that are currently being made are pretty bad and all but useless with the milodon style seals unless one polishes out the imperfections where the milodon O-ring sits. This is best done on a lathe. I'm going to bet your issue is the guide clearance /and or seals
