engine cutting out @ 4400rpm

Yes it could be dist. You say timing is fine, but is that at idle or at 2500-3000 rpm? If timing is 10 to 17 at idle that would be good for a mild to high lift cam. But you will need at least 32 to 36 degree to come in at 2500. What valve springs do you have? A stock weak spring could start floating at 4400 and limit revs.