How much horsepower are you willing to lose? Stack injectors, I assume you mean vertical, will cost you a lot of horsepower. ( unless you are willing to cut 12 holes in your hood)
The reason is the length of the air charge. Run vertically with clearance for an air cleaner and so the air cleaner doesn’t rattle against the hood will yield you something like a modest 4-5 inches at most. However if you run them the proper length horizontally you’ll pick up at least 20 horsepower over the carb set up. That’s simple just grab a fuel injection set from a 1975 or newer Jaguar.

Something people with Weber’s don’t tell you is how little power they actually gain over the stock carb set-up.
I built a full out racing V12 ( 13.-1 compression, bored and stroked to 7 liters . Ported heads, bigger valves, racing camshafts, and tried to use Weber’s 44IDF’s 340 horsepower if it fit under the stock hood. That’s after spending over 3 days on the Dyno and buying $1800 worth of jets, air correction, etc etc etc.
then I replaced the Weber’s with the slightly modified carb manifold that had been modified to use 4 SU carbs( HD8’s) in less than an hour I was over 450 horsepower.
The reason is because the distance is too short.
See How long the manifold is on either the fuel injection or the stock carb set up? That’s how long you need based on using the stock camshafts.

Alternate camshafts change things and if you plan on driving around at 9000+ RPM with the right cams you can use those short air horns. If you want to stay closer to the factory redline there is little additional power using Weber’s.