There are many turbo upgrades. How much does he want to spend? Buschur www.buschurracing.com has a 20G-9 upgrade that bolts to the stock manifold or he could go with a turbo kit like a GT30. There are a few things he would need in order to get the full potential of this turbo though.

I would recomend doing all the supporting mods first before turbo upgrade like cams(revolver), head studs(ARP), clutch(ACT or Exedy), upper piping, lower piping, injectors, 255 pump, front mount intercooler, and 3 inch turbo back exhaust.



These mods will get him started:

s-afc or custom flash
walbro 255 fuel pump
boost controller @ 21 psi
3 in. turbo back exhaust
upgraded bov to hold boost
K n N drop in filter

Stock turbo 26psi on race gas I made 373whp 385trq, but I also had cams and AEM.