Replacing Closet Elbow, but Joist Bay too Small

[MCSwe]

We're remodeling an old, old bathroom. The closet drains to the stack with a cast iron 4" elbow, with a 1 1/4" heel inlet for the bathroom lav and tub drain?!?
There haven't been any drainage issues (probably b/c water pressure is so low). But since we have it open we want to increase the lav/shower line to 2 inches.

Only problem is, we have to cut the cast iron elbow to run a 2" line. And there's nothing that will fit in the joist bay that could replace the elbow, without putting the toilet in the middle of the room. There's about 6" of clearance from the bottom of the cast iron stack tee to the bottom of the toilet flange.
Any tips or tricks for a new closet bend situation?

We're trying to meet UPC, but at this point will settle for best/safest option.

 

[Terry]

Remove the arm from the hub, replace with 3", add a 3x2 wye before the 3" 90 going up for the toilet.
Use a 14" rough bowl to move it back 2" closer to the wall.

 

[Sponsor]

 

[MCSwe]

Remove the arm from the hub, replace with 3", add a 3x2 wye before the 3" 90 going up for the toilet.
Use a 14" rough bowl to move it back 2" closer to the wall.

Thanks Terry. 3" inch 90 up to the toilet, does it have to be a longsweep? Flange would be too high if so.

 

[Terry]

On this one I used a medium 90 and a spigot closet flange. I have also used a spigot medium 90 and a hub flange. Make sure you make your measurements first to see what works.