18" Wheel help

So here is another curve ball.. I just found a B-Body 8.75 it says 68-70, will the 489 center section off of my a-body unit interchange?

Yes, the 489 pumpkin will interchange fine.

The nice thing about the wider B-Body axle is you might be able to use the same wheel on the rear as the front if they are both higher offset. That's how I can run a square 17x8 +30 setup.