400 to 451 stroker questions

That's the point I was trying to get across with my first comment. Not all 230 blocks are the thick main web blocks. Heck, a hard block fill to the bottom of the freeze plugs will add a lot of strength and still cool on the street.
Yep, I have a 73 630 casting I'm not worried about it. But the real beefcake 230 would be a nice piece