Steel Ball Run

Originally thought to be a "standalone AU", Steel Ball Run (スティール・ボール・ラン) has been officially declared a part of the Jojo's Bizarre Adventure series starting from volume 5 – incidentally also the same volume the series underwent the change of moving it's serialization from Weekly Shounen Jump to Ultra Jump, a seinen magazine. Aside from the chapters being longer in page count, the switch from a weekly magazine to a monthly one had a noticable impact on the art, as Araki seems to go for a more detailed, "naturalistic" look for his characters – the shift in style can be seen starting from volume 7-8.

Plot Summary
After Pucci is Killed by Emporio, The Universe's full transformation was halted and as a result became surprisingly similar to it's "Original self". The story this time around begins in 1890, the new universe. The series stars Gyro Zeppeli, who uses a set of steel balls that spin incredibly fast, and Johnny Joestar, an alternate universe Jonathan Joestar, a former hot-shot jockey who was crippled by an angry (most likely nervous) man who shot him. They race, along with others, in a mad-dash across America for 50 million dollars and possibly something else...