Atomic Four alignment

Thanks for the input on removing the engine. Before I pull it to replace the motor mounts and install the PSS shaft seal I thought it would help to get some input on the alignment once I put the motor back in. Is there a true way of doing this or is it more like eye balling. I can set up the new mounts to the existing height of the ones that I'm taking out so the angle is close but the port to starboard alignment is in question. Any help would be appreciated. My thought was to use some 2 by 4's against the starboard settee and side of the block. I won't do anything until I get some advise from this forum. This is on an Ericson 27 hull #1287

The key is to align your unconnected prop shaft so it's centered in the stern-tube, and secure it that way with the prop shaft coupling attached to the inboard end. Mount the engine so the transmission coupling mates up to the shaft coupling with an even space all around the edge. Use feeler gauges to determine if the plates are parallel. The relative alignment to the cabin furniture isn't important.

Nigel Calder's book always has good advice about these sorts of things.

Nate