360 block limits
Learning curve? If that was all there was to tuning EFI, everybody'd have it. I have a local friend who does high end restorations and builds. Almost all are LS powered with some sort of aftermarket EFI. Almost every one of his ends up "unfinished" because once he gets them "running" his customers rarely want to spend the 800 or so dollars to send it out to get it tuned. ......and to get them dead right, you have to have a dyno. I always thought that was rather funny that a customer spending between 75 and 100K on a build or restoration balks at 800-1000 for a tune, but almost every one of them do.....and then their junk only runs as a shadow of itself and they ***** to everyone they can find what a shitty job the builder did. No, there's much more than just a learning curve. At least with a carburetor, you can figure it out between you and the dragstrip.
I understand what you're saying but still I think learning curve is correct, there's quite a bit of prerequisite knowledge involved in getting started with EFI, and a lot of it isn't intuitive but all the information is available.
Sometimes people act as if EFI tuning is some kind of black art. But if I can learn it then anyone can.
(I had written/deleted a somewhat lengthy summary of some of the more common pitfalls which people fall into when trying to tune EFI for the first time, including inaccurate sensor calibration, injector scaling/data and altering the VE table with fuel trims active/enabled. But this is all really better left to a more relevant thread)
It's very optimistic for people to think they can just "figure it out as you go" and do a whole bunch of "let's see what this button does" and end up with a well optimized engine.
The good news is that there are resources available for those who want to learn.
I don't think it's strictly true that you need to have a dyno to tune EFI, especially with how comprehensive modern datalogging is.
But for a road car...no matter how much steady state dyno time you shell-out for, you will absolutely need on-road feedback to take the rough edges out of the tune.
The biggest advantage of a steady state dyno isn't fuel related at all. It's the ability to optimize ignition timing for MBT while avoiding knock, and this is equally true of both carbs and EFI.
That being said, I probably wouldn't use a 75k build with a professionally built engine as my first ever "test mule" for learning how to tune EFI.