The afterglow on this model is up to 60 seconds in very cold temps, probably 5-30 seconds in more normal temps. When warm, afterglow is near zero. I don't think this is a glow issue. Sounds fuel related to me, either injector, or delivery valve seals. Preferred timing spec is 14° but one degree off won't make much difference. I'm assuming that cam timing is ok and the chain isn't stretched (you have checked this, right?).
Or.... I hate to go here, but... what's the oil consumption rate? A good 60x engine should be 4000 miles per quart or better.
