When nothing less than 'more' will satisfy you, go with Banks Big Hoss Module. Big Hoss is a calibrate-to-order module, in up to 5 power levels (for 1994-03 models), that adds up to +120 hp and +233 lb-ft (with recommended airflow improvements). A pyrometer is recommended (see the Gauge section under Instrumentation). Tunes pulse width and timing.
Up to 5 power levels:
Level 1: up to +45 hp & +79 lb-ft
Level 2: up to +60 hp & +111 lb-ft
Level 3: up to +85 hp & +151 lb-ft
Level 4: up to +100 hp & +215 lb-ft (Levels 1-4: emissions compliant)
Level 5: up to +120 hp & +233 lb-ft (Non-street, high-performance use only)