Q: I just finished rebuilding the 5.0L engine for my Fox Body Mustang. I made the following modifications:
- World Products Windsor Jr. cylinder heads with 58cc combustion chambers
- Ford Racing X-303 camshaft
- Trick Flow Street Burner intake manifold
- 70mm throttle body and EGR plate
- 73mm Mass Air meter
- BBK cold air induction
- BBK adjustable fuel pressure regulator
- Crane PS 91 coil
- BBK 1 5/8-inch primary headers, 2 1/2-inch dual exhaust, H-pipe with converters
I am reusing the stock 19 pound/hour fuel injectors and electric fuel pump. The engine doesn’t feel as strong as I think it should. I added a 140-amp alternator which helped a little. Would a Crane HI-6S ignition help? Should I upgrade to 24 pound/hour injectors? The engine has just 1,600 miles on it, so it’s barely broken in and I haven’t gotten on it hard yet.
A: The modifications you’ve made are good ones. We’d start by adding a larger Ford Racing 190 liter/hour fuel pump and either the Crane HI-6S ignition or an MSD 6A ignition. We’d also adjust your fuel pressure with the BBK regulator. Adjust from one to three pounds more or less than the stock pressure (45 pounds), depending on what the engine likes—don’t go beyond this range. Take a look at the spark plugs as you do this (here’s a guide to reading spark plugs). The plugs will tell you if the engine is running rich or lean, although you can also use an air/fuel ratio gauge if you have access to one. You may very well need the bigger injectors.