Older ones had it too. I believe the 6.0 and may be the 7.3has it but i could b wrong.I know for a fact the 6.4 has it. It is a little spout that comes up at the bottom of the cylinder and spits oil under the piston to keep it cool.... Its really only needed on diesel engines due to the high temperatures in the cylinder.
The old idi 6.9 and 7.3 diesels had it also. The pistons can get very hot in a diesel engine, especially if they are overfueled. We try to tell people who love to turn their engines up and blow black smoke that they are getting ready to melt the pistons in the engine, but some don't listen and end up ruining it anyway.
Some of the big time diesel truck engines have a composite piston with a steel top and a aluminum bottom.
the 300's had a problem with pistons disintegrating, probably because their low torque curve caused high cylinder temperatures due to high combustion pressure. regardless of whether or not it was necessary, ford added oil jets to the rods on the 300, however I believe it was necessary
How would it kill oil pressure? This has been done for many years on production engines as well as race engines and is a proven method for reducing piston temperatures. It's not just a hole where oil flows out of. The pressure is maintained by the sizing of the jets, or the groove sizes in the connecting rods.
I'd have to see one in person to figure It out..lol iv never torn a motor apart that has one..iv never heard of them until my friends miata, but I never saw a jet on the rods of the 1995 1.8 miata motor we tore apart..