Early and mid 90's Bravo 1's. Factory drives mated to 330-400hp Chevy BBC's.

What no. of hours is typical before rebuilding/replacement is neccessary?

Run it until it breaks!!!! Just keep the fluid changed every 25-30 hours.

As much as 600-900 hrs on some of them.. Keep an eye on the magnets for metal particals. Heavy fuzz mean things are loosening up.. and tapered bearings have metal run thru them, which loosens things up more..

Hope this helps.

As of last year my 1993 24 outlaw still had the original drive on it. It had a 454 mag, bumped up to about 425hp and for the last 3-4 years has had a 525SC. I'm guessing it 600-700hrs. they tore it down for inspection, and all looked good a couple years ago.

I had over 1000hrs on mine with 454 mags on a 31SS. We took them apart and they looked great, probably would have done another 1000.