with 3/4 pipe and 3 90 bends it will be hard to pull wire.
The most your going to pull will be 1or 2 circuits, which will be 2 or 3 #12's
is it pvc , aluminum, ridged, or reg emc conduit ?
I would use pvc if it were me.
We just pulled new service wire (#3) from a generator to the gen. panel...