Well the 2.3 is a highly detuned indestructible engine. It never came from Ford built for the purpose of being any fun in a car. Your buddy is going to have to dismantle the thing and build it properly.
The basic bore and stroke design is oversquare and it has a noninterference valvetrain which makes it good for revving. You're going to have to forget what power ever existed below 2000-2500 RPM and focus on opening it up for higher RPM.
First you need to throw out the stock N/A pistons. They are junk. Get some good quality lightweight castings or forgings, forged pistons if you are really going to beat on it with possibly an imperfect tune. You want to raise the compression from the measly 9.5:1 to, well, something higher lol. Pack in the tightest compression you can get without piston to valve issues (need to pick out a cyl head first, obviously). The 2.3 rods are good for way more power than you will ever see, and have piston cooling jets, BUT you could do better to get a longer more lightweight rod.
Match up all the piston and rod weights, have the bottom end neutral balanced, and the crankshaft bores align honed to reduce horsepower losses.
Low tension piston rings like the 5.0 frees up yet more power. I don't know if you will need a high volume pump, but I doubt it.
Factory 2.3 heads: deposit in junk barrel. I hear Esslinger makes a 2.3 head. Any aftermarket head you can find with bigger valves and an intake port that aims as straight downward as possible is good. Open up the ports to about an inch and three quarters and polish. Polish chamber and 5 angle valve job. Mild to radical cam with an adjustable cam sprocket so you can dial in perfect timing. If you are using a factory intake, gut any walls from the upper plenum and knife-edge the leading edge of the runners in the lower, port out to match head and larger throttlebody (not sure what size is good).
Exhaust side should be fitted with a ceramic coated 1-5/8" long tube header followed by 2-1/2" exhaust with a new 2-1/2" catalytic converter from NAPA or something. Mandrel bent exhaust piping only. And for Christ sake put a decent muffler and tailpipe on it.
Dispose of everything before the throttle body that constituted the old intake. Install a 5.0L air filter box (direct bolt in) and put a properly oiled K&N in it. Install a duct made out of whatever you can find between that and the throttle body, but it must be smooth inside.
Top it off with an MSD 6AL ignition box. Purchase a bunch of the Autolite race plugs (side gapped, will wear out faster) and on each one, use a marker to make a dot on the top of the ceramic insulator to indicate where the gap is. In each cylinder, test fit different plugs until you find one whose dot ends up within about 30 degrees of pointing straight up. The idea is to get the gap aimed toward the quench area, or the area between the valves, for faster and smoother burn. Get some good quality wires too and a new distributor cap and rotor. Set timing as high as it goes without detonation, 20BTC is about good. Higher compression may require better octane fuel, of course.
After breakin fill the engine with Mobil 1 synthetic 5W30 oil, or an AMSOIL/Redline/Royal Purple equivalent. Use a NAPA Gold 1515 oil filter, they are good. Fill transmission with synthetic ATF. Replace rear gears with deeper reduction ones and fill differential with Mobil 1 synthetic gear oil.
ok, let me know how that goes.
