Am I right in thinking that the Darton sleeves for a 427 need to be done on a used block? I remember somewhere that they don't like to do them on a fresh block, is this right? (Sorry for these few quick posts, but info I need to know)

 

A new block needs to be stress relieved. On the wet sleeved blocks, MID, I first rough out the block, have it stress relieved then do the finish machine work.

A used block has been stress relieved in service so no further stress relief is required.

I recommend any new block to be stress relieved whether being sleeved or not. Then hone the cylinders round with a torque plate attached, check the main bearing bores at the same time and align hone if necessary. Stress relieving a new casting will give you a much straighter, rounder cylindered block in service.

Steve