just a thought, have you tried taking the headers completely off, then sitting the motor with mounts onto the k frame? then once successful, you might find that your passenger clearance problem may have been solved. it still might be tight and the motor may wind up where it should be. then try fitting headers onto the motor. I don't know if your headers are single tubes or welded together, but single tubes are much easier to install. even though my car is an original hemi car once I put those same valve covers on they were almost hitting the shock tower. when I need to take them off, I have to remove the distributor & hope the exhaust rockers are in the correct clearance position. I know it's a royal pain in the butt, but once the motor is in place maybe the headers, or several tubes are wrong. just my .02 cents dave ss/ea #1355