what had happened to require the new head?

did you do a compression test?

if you really need the rod to crankshaft bearings, you might be able to fish them in by dropping the oil pan, then taking them apart and putting them back together.

if the bearing for the block need replaced, I have seen a mechanic do it in the same style once. Not sure how long they lasted. its not exactly proper install procedure.

It sounds like youve put a lot of money into the engine recently though.