There are few folks here who have worked with the late Mexican EFI in its original form.
Typically they put a Megasquirt2 or microquirt on to control things using the original TB/manifolds, this is a fully programmable engine management system. That can work with much larger engines, even supercharged, or E85 fueled.
I personally have not worked on the Mexican system, but I have worked on L-Jet and digijet, so I'll try anyway...
Its essentially an L-Jet or Digi-Jet (decendant of L-Jet) system, and uses an AFM to measure flow, so SHOULD have some headroom to work with a slightly larger engine with a stock or near stock cam. The AFM won't tolerate a wild cam, or really even many pretty mild ones, just stock or close, high ratio rockers are fine, its ~just the valve timing that's critical.
If Digi-jet, there may be an aftermarket "chip" for it but that would still be somewhat engine-specific.
Going to 1776 raises the compression a little, may required better grade of fuel, maybe not.
The AFM has an internal adjustment or two, but Google will have to guide you there, don't mess with it unless required.
An adjustable pressure regulator and "ballast" resistor in the CHT sensor line are traditionally also used to fix L-Jet on larger motors, by feeding a % more fuel in an adjustable manner.
I would borrow or buy a WBO2 setup to make sure its isn't running lean at WOT, or at least see if you can monitor the factory narrowband O2 lambda sensor with a DVM to make sure it doesn't go lean.
The engines ECU also uses it for mixture correction once warmed up, so you can't just unplug it, you'd have to tap in to the wires to see the voltage, it reads either rich or lean, the ecu will actually fiddle the fuel so it switches back and forth across stoichiometric AFR. (lambda=1 or 14.7:1 AFR)
This assumes the factory sensor is still good... They have a limited life expectancy, and can be easily killed if your old motor was burning oil etc. A modern wideband system as a replacement may be cheaper or at least a better plan.
Many wideband O2 setups have a "fake" narrowband output.
(its not really "fake", it's calculated, coming from a much better sensor) to keep the factory ECU happy.
Some of these have programmable "fake" NB outputs so you can run leaner or richer than the programmed AFR at your desire.
Normally they just report what a narrowband sensor would have based on the widebands AFR results.
I personally have had great results with the units from 14point7.com.
Also some of the least expensive setups, and one version is the only Open Source design and firmware WBO2 I know of if you are into that.
IIRC the std narrowband will read about .350-.500v at lambda=1
