the offset angle in u-jointed shafts create a constant motion that makes the needles roll which will then last a long time--IF you set up a shaft with needle bearing u joints in a perfect straight line it will SOON WEAR into a piece of junk that looks like a splined drive cross--

Seems that what they developed for angled drivelines killed off option of going straight---

On my raqce builds I have a piece of 3/4 wall thickness tubing 2.750 od that fits BBC / cleveland ford main sizes and the other end with a pinion support housing for a ford 9 inch which allows to set up perfectly straight at the settings for the 1/4 mile--yes u joint life is only a few miles but so is the lifespan of the car when run 1/4 mile at a time--