Is it hydro or cable clutch?
If its hydro, bleed the system out twice (as in, run the master cylinder almost dry, and refill, and repeat) to make sure all of the air is out.
If its cable, check to see if its adjust correctly at the transmission.
Chances are its some cheap autozone Chinese clutch with a bunk pressure plate that doesnt have half the resistance of the OE clutch. Which is fine for daily driving and such, but it'll never feel the same unless he gets an OE clutch, or better, put back in it.