Actually it's not brass, it's bronze that has been oil impregnated. You may not see the oil in the bearing I posted, but if you heat it up the oil will start to come out from the pores and you can see and feel it. To prevent a dry start up. I will apply engine oil to the input shaft. I use to apply a little high temp grease, but the internet told me that the soap in the grease blocks the pores. So I bought into that even though the grease has worked for many years on my installations. 30 plus since 1981
There's 2 killers when it comes to pilot bearing, one is improper bell housing alignment. The parallel and concentric alignment should be checked and adjusted on ALL installations. The second which also kills throw out bearings is continued application or riding of the clutch. So kicking it into neutral while waiting at long traffic lights will extend the life of these parts.
Oilite is also used in bronze and iron impregnated bearings. For some applications this would be preferred as it will last longer. However, the Muncie input shaft is not hardened and the metal will cause heat and wear on the Muncie shaft. The metal in the bushing overheats and starts to weld itself to the input shaft. Think of bronze with metal particles in it. The metal acts as an abrasive until it overheats and attaches itself to the input shaft.
Roller bearings are not advised for use on the Muncies for street use. The Muncie shaft is non hardened and when the bearing fails, Will damage the input shaft. When a bronze bushing exceeds it's life, you'll develop shifting issue, vibration, or noise, yet it is more forgiving than the steel contained in the failed roller bearing.
Oilite is a trademark of Beemer Precision but was initially invented by Chrysler in the 30's, so many bearing manufacturers will not pay royalties to use the trademark, but still produce a similar product.