Hypertech 121121 TBI Auto Computer Chip (91 C15/25 P/U 350) The product is 121121 - 91 C15/25 P/U 350 TBI Auto Computer Chip Easy to install The product is manufactured in United States Must run premium fuel Plug in and go, no wiring or soldering required 50-state street legal Use with stock temperature thermostat Allows the vehicle's top speed to be matched to the speed rating of high-performance tires