I know guys that will pull an engine block out of a salvage yard, run a dingle berry hone through it, assemble, and run it. It will run but it won’t be right.
There are ZERO aftermarket blocks out there that don't need the full machine work treatment: bore and hone cylinders (hone only if they come rough within .005" or so of finished bore size), align hone mains, square the decks.
The BBM blocks come with a 4.245" rough bore size, so they just need the cylinders honed to finished size, but they need everything else.
Don't let anyone tell you that they are usable out of the box.
In addition, you need to grind on the china wall to make the distributor fit, and if you use Durabond FP-01 cam bearings, each bearing has to be installed carefully to make sure it doesn't block the adjoining lifter bore. If you use the front bearing out of the FP-01 set, then you have to clearance it to make the distributor fit.
The blocks also need pressure tested and all of the
oil passages need to be eyeballed for drill throughs as well.
Not dogging BBM, but this is par for the course for any FE aftermarket block.