before the crankshaft.. I suppose if you take your time and slowly place it in but there is always that chance that you score the journal. Heads look good also,, who did the port work? I seem to remember there being some sort of study that was done a while back on removing the guide bosses.. exh removal was beneficial because it would open flow. Int removal wasnt a good idea because it helped direct the airflow towards the valve. with the bosses removed it allowed a swirling effect that would disrupt airflow. Hopefully someone on here can add to this. Great work tho it looks like you did a great job. Matt