If anybody is interested, from a wayback search I was able to find this info (of course their upgrade stages lol).
Delco/Mongoose Performance Packages
Stage I Power Pak 360+ Horsepower *
1997-98 LS1 Power Pak, Includes K&N Filter and Fuel Re-curve Vacuum Line
Stage II Delco/Mongoose 380 SS 380+ Horsepower *
Includes Stage I, Plus Ignition Timing Tricker, Throttle Body Coolant Bypass, 180 Degree Thermostat, Max Modified Air Flow Sensor (Exchange-Core Deposit Required of $125-), plus a Delco/Mongoose Performance Badge. NOTICE: Customers with a '97 or '98 should add an Adjustable Fuel Pressure Regulator, and a Fuel Re-curve Vacuum Line to achieve best results.
Stage III Delco/Mongoose 400 SS 400+Horsepower *
Includes Stages I & II, Plus Low Resistance Ignition System With Low Resistance Red Wires, Low Resistance Plugs, Aluminized Solid Steel Exhaust, (Other Exhaust Systems Available), Performance Badges.
Our Most Popular Package!
Stage IV Delco/Mongoose 425 SS 425+ Horsepower *
Includes stages I, II, III, Plus Long Tube Coated Headers, Custom Computer Programming, Max Air Intake System, Performance Badges.