Originally Posted by Pocket

"Better" depends on how the truck will be used. I'll try to sum up the difference a short and concisely as possible:

In a nutshell, a larger nozzle becomes more efficient - compared to a smaller nozzle - as the RPM's increase. But on the flip side, the larger nozzles are in essence less efficient at lower RPM's.

It boils down to fuel-per-time. Yes larger nozzles don't atomize as well, but as the RPM's increase significantly, the fuel-per-time capabilities of larger nozzles overcomes the differences in atomization. That's why a larger nozzle can run cleaner with less smoke and much lower EGT's at say over 3,000 RPM compared to a smaller/stock nozzle.

But that comes at a cost to lower RPM efficiency, where larger nozzles haze easier and have a much more difficult time dialing in the idle quality. Go really huge on nozzle size and you can actually see a decrease in fuel economy, especially at cruising RPM's.

So what are you accomplishing with a change in nozzle size? Simple. You're re-positioning the effective RPM range that you'll be utilizing.

Do a lot of heavy towing? Well you probably spend more time at higher RPM's, so moving up in nozzle size can greatly increase your towing capabilities while simultaneously decreasing smoke and EGT's. This of course assumes that tuning is done correctly.

Your truck never tows and you just want to increase fuel economy? Stick with a stock AC injector with stock nozzles. Keep the efficiency at the lower RPM range where the truck will live most of its life.

Originally Posted by lpzd

Not all versions of the 466 had AC injectors if fact I think only one did and pretty sure they had different nozzles . The AC was used in the t444e "high torque " but never in a Ford .
not tying to be argumentative just don't want anyone heading to diesel bone yard thinking they are going to find performance injectors .