The 525 rebuild was preventative. Cone Clutches were worn out and took several seconds to engage. The 600 boat is getting rebuilds this winter after ~90 hours. The rebuilds have only been of the upper portion of the drives. Gears, bearings, seals, etc. and of coarse Dollars. There is a lot of information on this site regarding the XR drives. Lowers are always checked and within spec so far.

Run some good fluid like what the bravo shop sells.

You should be fine with that.

I like IMCO Lowers with XR Uppers and a billet topcap. Max upper vertical is also a good addition.

thanks again everyone. Really appreciate the advice.