To know what kind of mods will help him we have to know his goals. If he is looking for an all out racer, stripping his car completely will help, deleting A/C if he has it, relocating the battery, remapping the ecu, roll cage, etc before he even touches a port and polish, stroker hit, higher compression ratio, knife edged crank shaft etc.. If he is looking for a grocery-getter, than suspension, wheels, tires, clutch, flywheel, and making sure the engine runs at peak efficiency are a primary mods. Of course this is just my opinion.