It might be that the 4th cylinder is screwing everything around.
On the boost gauge it is reading 4psi at idle and increases as the revs increase, as expected. I'll try to find this darn block breather, cant for the life of me find it. WIll have another peek soon.
Tim, it's only back firing and with black smoke cloud, from the 4th not combusting. Engine does not look rebuilt, worried about rings...
and we relocated the tubing to the brake booster, so nothing should be funny there.