It's a good motor, the modular 2v platform is tough and reliable and but you gotta understand something about them: You can't just flip one part in isolation and call it good and think it's going to not deliver you some surprises. The 2v motor is not a high RPM motor. It's a mid-range compromise engine in every respect. Biasing a 2v toward high RPM operation, even in a properly configured 2v engine, makes nice looking HP numbers on paper but it very often murders the low end torque production because people push the power band too far toward high rpm HP and, by definition, sacrificing low and mid-range torque production thus making the car kind of a dog at more the common operating RPMs associated with street driving. Too much cam and not enough head flow, too much head flow and not enough cam, lower than necessary compression ratios, etc... are all easy ways to leave a ton of performance on the table and end up spending $$$ in places that don't return or support power production.
3.73 gears are the right direction if you're biasing to just slightly higher rpm for your power band, pushing it out 1500rpm higher than stock. As RPM goes up the available pulse width is reduced so you need a bigger injector to be able to deliver the fuel in the available time slice. Ford had/has a habit of providing just enough injector for the factory configuration. More snot needs more fuel. You will want to bump to a slightly fatter injector depending on how fast you want to spin it and a number of other factors. 24-30lb/hr would be where I'd go on that. I started to run out of injector with 30's after 7500rpm in one of my other NA 4v cars. Factory rods and crank are a weakness particularly with rpm's at or over 6500. Factory rods and crank are surprisingly strong but if you want to be zinging to 6500+ rpm I'd replace them with something stronger only because every 2v I've seen self-generate a set of aftermarket rotating assembly inspection ports did it above 6500rpm. That said, not every stock bottom-end 2v I've seen winding out 7000rpm threw a rod or snapped a crank, but they were sure going to sooner than later.
If you want to make power then you're going to get into engine internals. No two ways about it. The factory heads are a limiting factor. So are factory cams. The OEM compression ratio is lower than ideal for a NA car wanting to make bigger power. Slap a Trick Flow top end (heads and intake) and some cams with 20 degrees more duration and a bit more lift, a cobra crank or aftermarket forged crank (kellog), forged I-beam rods, and pistons set up for 11:1 compression along with some 30lb/hr injectors and run it up to 6500 or 7000rpm. Should be a nice performer with your 3.73's but don't get your hopes too high with regard to dyno numbers. Area under the curve is what matters anyway and I'm sure you'll enjoy such a combo.
You really can't do much to these things without doing a tune. That's just how that cookie crumbles.
