Do the '93 ECMs have a shorter Max injector duty cycle? I am fine a/f wise down low but up top I seem to lean out a bit more than just a normal curve.

 

93's have 22# injectors, 94+ have 24# injectors.

So yes, your fuel delivery is a bit less, and the pulselengths you show will be a bit longer than the same set up with 24# inectors, but unless you're putting down ~380rwhp I doubt you'd have problems.

As for the ECM? no, injector duty cycle is limited by the time one rotation of the engine occurs, the ms lengths are the same for all RPMS.

While it's natural to have a calibration that runs a bit lean after the torque peak, you may want to hook up a fuel-pressure gauge just to make sure your pump isn't dying on you.

My LT1 dyno'd a crappy 245rwhp and 14:1 A/F on the wideband as the pump was starting to die. Three months later we slapped her on the dyno with a new pump and pulled 280rwhp. Pumps don't usually just fail... they typically "die off" like mine did (or so I'm told).