When there was no one else Howell was the answer. Now there are many who burn chips for these ECU's and it's possible and even slightly easy for someone computer oriented to set up and burn chips themselves. I've read some not too favorable things about Howell's programming. Could've been just wanking, may have been justified. No idea myself.
They're not an electronic carb! If you've ever messed with one of those a TBI is a huge step in the simpler yet works better direction. That isn't to imply that a TBI system is terribly smart because they're not. However my experience with them has been that they work surprisingly well considering what they are. I think being able to drive from sea level to 12,400' in elevation over a two day span without any issues or change in drivability (other than lacking power like all NA engines do at those heights) speaks pretty well for the system.
They need a tach signal, a TPS, a coolant temp sensor, an O2 sensor, and a MAP sensor to work. They work better with a VSS signal, but it's not an absolute requirement and most transplants don't have that. The wiring loom is pretty simple and all of it can fairly easily be pulled from one donor. Will need a 15 psi min fuel supply system with a return.
Dead stock they start to run out of everything at about the 300 HP level. There are tunes and tweaks to push past that, but by that point I think that some other EFI system should be chosen.
With comparable displacements I'd expect to only need a custom tune if you're going to give the ECU timing control as well.
