Gearbox comparison + Belt Drive parts

What is the difference between this Gear reduction box, Annovi Reverberi AR AR1601 1:2.24 Reduction Gear Box for 1-1/8″ Shaft – or Annovi Reverberi AR AR1670 1:2 Reduction Gear Box for 1-1/8″ Shaft –

The reason I ask you guys is because in the first link that I sent has the x cross flange and the 2nd link does not have the x-cross flange. I dropped the the x-cross flange mount part and it broke into a few pieces, so my Question is, Can you mount the gear box without the x-cross part?

I saw gx690, ((thats what this gearbox is for a 690)) engines with the same gearbox but without the xcross. Can I mount either way and if not are there any other alternative gear boxes out there that are not from from AR that would work with an 8gpm pump?

I guess I can go with a belt drive build as well, but I am not sure if there is a belt and pully kit for a gx690 and an 8GPM pump. To be honest I don’t know all the parts that I will need for a belt drive unit.

I already have the skid, battery box cover, and gas tank as well as a 50gallon tank with all plumbing fittings.

Any help would be greatlt appreciated.
Best Regards,

I got mine from Russ at Southside Equipment in Louisville. 8gpm pump with GX630 and GP gear drive.

I believe that one gear is for 1450rpm, and the other is for 1750.