Whats the difference betweent he two? I see most boats that use surface drives use BPM or Arenson, but i know Bud Light uses trimax. What advantage do they see by useing them?

Bud Light uses Lathem,

GEICO/JBS/Aqua/Cintron use BPM

CMS/CRC Merc # 6

Advantage is strength, predictability and durability.

I didn't know Latham built a shaft drive??

Arneson/bpm same thing, BPM has a different thrust tube length and is trimmable only with an Arneson socket. BPM uses a gear drop only some Arnesons us a chain on one side.

Trimax(x-bud) has a pivot at the transom. There is a small trim on some models 1.5 inches but the flange inside trims as well. The propshaft has a bushing that is lubed by water. The shaft is exposed except the bushing area. Internal drop box.

Hope this helps.

pat W