I am sorry I referred buckets as lifters, same job, different name. I was asking if they had been changed from stock and if there were any clearance and lube issues had been checked, as well as spring tensions (sometimes after a beating they get a limp spot)
In the operation of settling airerated oil it does allow a certain amount of oil to build up dependant on agitation of oil. If the AOS does not work fast enough you end up with volume. Did rings get gapped properly for extra heat buildup? Does the code hit right away and is it always Misfire Cyl 4?
You said that the motor has popped at least 2x. That is not a normal occurrence for any build.
I am here to try and help with a question. If you do not want help it's all good by me, just trying to be a nice neighbor.