Next up is the FRPP throttle body. The first thing to do is remove the throttle cable. Gently pry the plastic housing downward to release the ball from the socket. | 
Stick cars can skip ahead here, but AOD owners will need to remove the throttle valve cable for the transmission next. Pull the clip and push the pin downward, and be sure not to lose the bronze bushing. | 
Disconnect the throttle-position sensor and IAC motor; then unbolt the throttle body. Since we used some makeshift bolts to secure it after our intake install, we hit up the local parts store for some carburetor studs to mount the new piece and make for a cleaner install. |
You'll need to transplant the idle air control valve (IAC) over to the new throttle body. If your car has high miles, now would be a good time to split the valve in half and hose the insides down with some brake cleaner to remove the carbon buildup. HP's tech Steve Duncan prefers to leave it as is if it's not presenting a problem. If there's an abundance of carbon buildup, then you can clean it by spraying it and working the plunger inside. | 
FRPP provides a new self-retaining, plastic bushing for the throttle valve cable, but Duncan's experience has proved them to be fragile if they have to be removed again at a later date, so we opted to reuse the bronze bushing and clip from the stock throttle body. You may need to file the hole a bit to get the bronze piece in. Just make sure it's a snug fit. | 
The FRPP throttle body includes a new throttle-position sensor, which needs to be adjusted using a multimeter. Simply loosen the Allen-headed bolts and rotate the sensor housing until you reach the desired voltage of 0.900-0.999. |
Despite the reading on the meter, we settled on 0.997 volt. | 
The throttle body's peak numbers were down a bit, but from looking at the graph, you'll notice a big increase in low-end torque. You won't miss 4 hp, but 10 lb-ft of torque will probably put you back in the seat just a little harder, not to mention get your Mustang moving faster. We also suspect the throttle body would be better suited to an engine that was moving more air, which might be in this engine's near future. | 
The FRPP Cobra rocker arms come with everything you need short of a set of valve-cover gaskets. We tapped the expense account for a set of Fel-Pro's blue reusable gaskets; FRPP provided the hardware for the rockers. |
After removing the upper intake manifold, the valve covers were next. We were able to leave the spark plug wires on; we just removed the looms from the valve-cover studs. | 
The FRPP Cobra rocker arms come with everything you need short of a set of valve-cover gaskets. We tapped the expense account for a set of Fel-Pro's blue reusable gaskets; FRPP provided the hardware for the rockers. | 
With the rockers and valve covers installed, you can now put the upper intake back on. |
The rockers picked up 4 more horsepower and 3 lb-ft of torque at peak. Gains were seen across the powerband, which means all of the extra ponies are available all of the time, and not just at the gear changes. Our three mods have now generated 9 hp over our baseline. | 
Having noticed that our air/fuel ratio was rich with an average of 11.6:1, HP's Tony Gonyon offered to add a little more timing to the computer using a piggyback chip from SCT. After removing the stock A9P processor from the kick panel, he removed the factory tamperproof covering to access the port. | 
The leaner air/fuel ratio offered up another 6 peak horsepower and 3 lb-ft of torque over the three previous mods. Compared to our baseline of 228 hp, we picked up 15 hp and 8 lb-ft of torque, and those gains were made across the powerband, which means the extra ponies are usable at just about any rpm. |