5 thou with a Rock Crusher wont hurt too much. Not sure if you can get offset dowells (or even need them for 5 thou), I seem to remember we used to get 10 thou as the first size available - have been out of that part of the industry for too long to clearly recall them, but think they were specified for an auto (more critical with the flex plate/torque converter alignment) so as not to shag the converter seal, than the front input bearing of a manual box, which can take a slight mis-alignment much better.

Nice torquey weapon... sideways in 4th with a dip of the clutch.

Keep the clutch splines well greased and the spiggot bearing "only just" greased.