Hemi darts question........ LO23 & BO29?

A guy was asking me what's the different between the BO29 and L023 Hemi darts ...I couldn't answer that so I need some help....

Thanks......

PS....they all came with Dana's right ? This is how we even got to talking about this, there was an ad for a supposedly LO23 hemi dart but it said it had the original 8 3/4 with 4:86 gears and I thought that just didn't sound right.