[DavidNJ]

I think it is more like $3300. I'm not sure how much extra machining is needed. Cleaning, boring the cylinders and mains, honing the cylinders and mains, decking, etc. might be $1000 or so for a used block.

Not really important. You should make your numbers with a 428. However, why not use the 4.25 stroke with BBC rods? The cast kit--which KC was selling in a Pond aluminum block for $8k--is less than $2k balanced with rings and bearings.