I've gone back and forth on this over the years. Originally, I bought a digital replacement for the microfueller and have it on ebay now:
https://www.ebay.com/itm/Turbo-Fueller- ... SwsltgOaue
pros - plug and play, precise digital mapping, keeps the look of the additional injectors, cheap solution
cons - still a piggyback system, doesn't control spark in boost
Then I came to the conclusion that it's better to just run everything from the main ECU. Fueling and spark in boost will be more precise. There are two solutions for this:
1) The blowerworks MAF (
http://blowerworks.net/sensor.html: this uses a modern blade-style MAF with a new bin to handle the change and remove the airflow calc limitations in the stock bin.
pros - simple installation, just one wire gets moved in the ECU connector, accurately calculates fueling for whatever air the turbos throw at it, everything else remains stock (easily reversible)
cons - lose the look of the additional injectors (or leave them in but disconnected), a little pricey for what you get, have to buy larger main injectors, too, and some of the factory tune clunkiness/limitations remain.
2) The dynamicEFI EBL Flash (
http://dynamicefi.com/EBL_Flash.php): you replace your stock ECU with a modified GM ECU and convert to speed density in the process.
pros - designed with boost in mind (2 or 3-bar MAP sensor), retains the factory dash functions (trip display), full control of fuel and spark up to high RPM (8k), added analog/digital inputs for things like fuel pressure, WB o2 sensor, etc., can do VE learn off your wideband o2.
cons - requires repinning of about 6 wires in the ECU connector and plumbing in a MAP sensor under the hood, have to buy larger main injectors as well, also lose the look of the rams horn injectors unless you leave them in as dummies.
These two solutions are only for the '87-'89 MAF cars. There are solutions to the '90-'91 speed density cars, but I don't think there's one that allows you to keep the dash/trip functions working (the microfueler replacements obviously do).
I'm running the EBL Flash system in my Guldstrand Grand Sport 80 car, and it's very slick. The tunability and what's up display are awesome. I plan to follow suit with the B2K when I have the time.