Hp and computer questions

You are going to do one or the other, not necessarily both. By that I mean, when you order your mass air meter, you will have to order one calibrated for whatever injector size you are using. In otherwords, if you switch from 19# injectors to 24# injectors, you will need a mass air meter that is calibrated for 24# injectors. That's it. No need for additional computer calibration...the computer doesn't care as long as the two match. If all you are doing is a injector swap, then this may be the most economical choice.

On the otherhand, it is possible to calibrate the computer to match the injectors and not have to switch the mass air meter. In that case, you don't necessarily need a new mass air meter. However, don't plan on upsizing the injectors and then driving over to the shop for computer recalibration...you'll be lucky if the engine runs well enough to get it on a trailer. If you're going to do that, then have the shop do the injector swap and calibrate the computer while its in their hands.

That said, if you have a stock or seemingly restrictive mass air meter, then it might be advantageous to go for a larger meter and forgo the computer cal.

If you are anticipating drivability issues because of other mods (cam, heads, intake, blower, etc.), then you may want or need to get the new mass air meter AND have the computer recalibrated.

My .02