Rear tires after moving springs

What would be the point of moving the springs into the frame and not tubbing it? I mean that is the whole point of going more than the 3/4 inch required to get to flush with the inner tub wall. Now you are ready for 2 inches of tub. And then narrowing. And then almost any tire.
As it is, you are limited to the stock tub size, but no longer limited by the spring.
Because of the new shock orientation, and the highly arched SS springs, body side shift motion may be an issue for you. So although the 325s might fit in there, if perfectly fitted, I doubt they will endure much cornering,before rubbing.
It is my opinion
that 295 s will be safer. These will work on 10s at 24 psi. 24 is Not ideal for cornering, but for a streeter they are not sticky enough anyway; and drifting is way big fun.