OK I have the block ready to drop off at the machine shop as well as the crank to be inspected and turned if needed. Now before I head out, do I absolutely need the new pistons for reference before they can work on it?

 

If it was me, I would just call over there and ask them what they need.

 

They shouldn't balance the rotating assembly without actually having your pistons and rods. The whole point is to balance the crank so that it properly counters the weight of the actual pistons and rods attached to it.

 

They can bore it but not hone it until a piston is in hand......thats where you get the piston to wall clearance. I would let them inspect it and You should buy though them also...so if something is wrong or won't work thay can eat it