340 Rebuild "Musts"

Just my take;
- For 400 HP on the street, and a .020" or .030" overbore, I would not sonic test unless I had reasons to doubt the block. BTW, you can get .020" over pistons from KB for this, and if you go .020" over on the 1st bore instead of .030", you can get an extra boring cycle out of the block.
- Align bore is an option in my book at this level. I've done a dozen or more 1.2 HP per cubic inch engines and a few 1.75 HP per ci turbo engines and all have done fine on bearing wear and everything with no align boring.
- I assumed when I last asked for 'decked' that they would 'square deck' since they knew we doing a good build. My assumption was wrong! Ask for 'square deck'; that makes the deck perfectly perpendicular to the bores. It will still run fine is not perfectly square, but measurements of piston-to-deck height get harder to make consistent.
- Some form of crack detection exam of the block is an insurance policy that I like to pay for.

BTW, your path to 400 HP will be easiest if you get flow into the heads. The cam can be made bigger to compensate, but then you will give up low end torque and make the motor 'peaky'. If smooth street driveability is your goal, then start with head flow, so you can keep the cam durations down for better low end torque.

Ditto for putting the SCR up in the 9.5-10.0 range: torque band will be wider, and low end RPM driveability better.