Both Lifter and Piston bores have room to hone to fit with the 4.50 block. Not sure what the sleeves are made out of and I would rather Hone the sleeves for a piston fit than bore and hone them. Not in a super hurry so 6 weeks is not that far off.for me. I still have another option for a 572 another friend had FHO build one 10 years ago and never used it. A mild stireet motor World Block and Stage V heads but he is still undecided on what he is doing with it. The Michell block is 6 weeks away and Eddy Heads might be the same time away. Going to start looking into what is available for Crank, Rods and Pistons and see what is better to order a balance unit or one piece at a time. I do like the Callies Crank but it is not a cheap adventure.and likely is over kill for what I want to build.