XR or XZ
 

Can someone tell me what the difference between an XR and XZ drive is?

Take a look at Bam marine's web site. They have a good comparison on all the bravo drives. www.go-fast.com.

Main difference is that the XR has straight cut, net forged gears, compared to the XZ helical gears. I've been told that the XR is not quite as efficient, but wears rather than grenades when subjected to large amounts of torque.

i put 970 hp each on a set of 1.36 xz's last year with 125 hrs on the pin. ran great on my cat with no problems. i run them hard. ask anyone if i cant break it it cant be broken