increasing horsepower/low and mid-range torque

[chiaronate]

hi again. i have a 1994 mustang gt with automatic transmission and 2.73's. i was wondering how to greatly increase horsepower, without losing low and mid-range torque. i'd like to do this without a supercharger, turbocharger or nitrous. i read in a book that i have ("how to build and modify ford fuel-injected 5.0-liter v-8 engines") that "The stock 5.0 HO is optimized for torque. no other combination of parts produces as much low-rpm torque than the stock motor." i was thinking of buying a kit, such as the systemax kit from holley, but i'm guessing that it will ruin low-end power. you guys have been a great source of information in the past, and any info you have i'm sure would be very helpful.