The guy I have do mine who is very familiar with Y blocks is New world engines in Monmouth, Maine. He is young, probably my age, just slightly under 50. but his work is meticulous. he specializes only in vintage engines.For me he line bored my block, squared it, decked it, bored cylinders, polished my crank, rebushed my connecting rods, shaved my heads, intake ports and installed new valves, guides, I furnished the springs and keepers from Mummerts. Honed my Bone!! oh wait, my wife did that part.
I then took all components to a balancing shop and within a couple days he had everything balanced from the damper to pressure plate.
I then did all the assembly myself.