X block sonic test

I'm with the majority. Keep it a conservative bore size and save it for future freshening. Extra thick walls will keep the bores more stable & round. 4.04" is a good start if it gives the pistons proper clearance. They may not be as expensive as a bigger, less common bore. Deck should always be checked as part of the "blueprint" process to make sure everything is flat, equal, square, etc. with consideration to tweaking compression.