You will need a Vortec TBI intake and a driver's side exhaust manifold for Vortec engines along with the EGR tube. You will probably need to install a different chip as well.
could both sell you what you need for the swap. Also, check out CFM Technologies
for they specialize in TBI performance.
If you have the cash, you should also consider Edelbrock's Multi-Point Fuel Injection Conversion Kit
. I just put one on my 94' Suburban with the stock 5.7 engine, but the Vortec conversion is advertised to produce 265 HP and 340 ft/lbs. It comes with everything except the in-tank fuel pump and exhaust manifold or EGR tube kit. You can buy their pump or a pump for a 91' Firebird GTA at a local parts store. It is an easy swap and works and performs as advertised, at least for the stock engine.
Good Luck! Ed. www.edgesz28.com