Hi There,
I am doing rough in for the bathroom in the basement. I have cut into concrete floor and already attached 3"abs pipe to one of the drain lines coming from first floor. NOW in order to maintain a downhill slope I have to raise the toilet flange.! (about one and a half inch) above concrete floor. Shouild I use shorter sweep for connecting to flange or should I raise the floor in that space.

Hi Khush

Have you tried using a street elbow and regular flange, or a street flange and a regular elbow? If not, one of these setups should work for you. Worst case, you can always use a short pattern VENT 90 or a 3" ptrap 90, but these are a last resort...;)

One of the options mentioned should work for you!

Mark