how large a bore with a sleeved block?

Contact Darton Sleeves......about as straight an answer as you'll get..........I had the same thought, and guessing based on what was done with the sprint car block, 4.25 would be the largest you could go, in therory

Darton did market (don't know if they still do ) an interlocking sleeve kit for the 5.7 Hemi......no deck left, sleeves were free standing and studs up from the bottom of the case to secure the heads

OOOPP"S my mistake..........kit was/is for the 6.1