340 Rebuild "Musts"

I'm with RAMM on most of his points although I use a 5/16 drill bit for the main feeds because that's what I could get quickly at the time years ago.
I own a good, certified sonic tester. I get paid to test others blocks, including some shops'. I would not sonic test a stad bore block going +.030 unless it was for a longer-than-stock stroke. It is not a necessity. There are times I do consider it but a 400hp 340 ain't one.
I do always line hone. That's so the CNC can have a confirmed straight centerline to index off of.
I always square deck - height TBD depending on the pistons and combinations but I can set deck height where I want that way, and know it's right for all of bores.
A good performance valve job on the factory heads will supprot the power level. I'd run a solid lifter because it will make the number and add some lower end grunt over a hydraulic. But that adds valvetrain cost due to the need for adjustability. If not, a hydraulic with the stamped steelies can certaintly make that power level. I've made 480 going off mph and weight using them and a hydraulic shelf grind cam.

I have no idea why redirecting oil or full grooved mains or "tight crush" would be needed here.