replumbing closet flg

I am a newbie DIY'r, and got myself into a possible pickle. I replaced tile in my 1st floor bathroom, and for reasons I thought was good at the time, decided to remove the closet flange (old tile was under it, and I wanted to ensure new tile was replaced in its place for rigity and thought it would be easiest to get the old flg out of the way entirely. I have a full unfinished basement with easy access underneath, so i cut off the 3" PVC downstream of the 90 elbow, and planned to splice in a new elbow/closet flange. However, now, I here is my pickle...

I have everything cut to size, and I started to trial fit. At least I am that swift. I thought I'd use a (standard I think) 90 elbow with couplings to accept 3" dia inside. Then I thought I'd splice a short 3" dia segment inside my flange to elbow junction. here is the rub. i have an interference of ~ 1/2" overlap between the two pieces. Is is permissable to hack off a bit (~3/8" length)from each side of the joint (ie closet flange extension and 90 elbow each), so the flange is flush w/ the other and I can fit in a 3" segment. Or do they make closet flanges with differnet adaptor lengths? or is there another recommendation. i certainly cannot drop the horizontal pipe to make it fit, or then I'd loose the grade slope for drainage purposes.

ps - I also thought an option might have been to use a 90 elbow, where the side to attach to the flg is a 3" dia segment to fit INSIDE the flg adaptor, but then I only have ~1/2" inside the joint tobond together, and I am worried this is not adequate overlap. thanks.

what about using a street 90, it doesn't have a bell on one side rather fits into a bell. Or, use a 45 flange and a street 45 or some fitting to make it work.

You could use a 4x3 elbow to make your connection. It has a 4" side and a 3" side. Then buy a flange that fits inside a 4" pipe. There is no stop for the connections to bottom out on.

thx for your input! after heading back to the plumbing store (I have learned amatuers spend a min of 5 trips to the store), and thinking thru your ideas, I happened to notice i actually grabbed the wrong 90. I had a midsize one, instead of the largest. I got that home, and worked like a charm with a 3" spigot flange. Figures, as an engineer by trade, I overthought the problem. As always, simplest solution is most likely the correct one.