Stock Ford meters are not 'calibrated' for an injector size!
Ford calibrated their meters the right way... meaning that the meter corresponds to the ecu.
Saying that the 93 Cobra MAF is 'calibrated' for 19's is simply adding to an already confusing subject.
I would call it a lie, but others will argue with me...
A couple of guys have reported using a 93 Cobra MAF on their A9*/19Lb setups with good results.
This is not ideal though, as the output of the meter does not match the way the ecu is interpretting the MAF signal.
A better option would be a MAF from a 94-95 Mustang.
Do a search, there is a TON of info on making this work. Actually, I think there is something in the 'Tech Thread Index'
Personally,
I would use the 94-95 Mustang meter, as it is KNOWN to work properly.
So far as I can tell the 93 Cobra meter makes the car run, but little else is known...
Just to be sure this guy is actually selling a Cobra meter...
The sensor should be marked 'F1SF'
The housing should be 70mm
When you say you are getting a 'tune'
what do you mean?
dyno time with fuel pressure and timing adjustments?
custom chip?
Good luck,
jason