With my motor build I believe I'm getting close to hitting the limits of my Bravo I. I've made a few changes since the original build upping the power a little more. Now, a long time ago Griff told me my Bravo I (1990 or '92) gears were stronger than post '00 Bravo I's. He stated if I did break the drive than swap to a Bravo X upper, not the XR. Has anyone done this? Is it something I can just get the internals for and rebuild my upper, a kit, or is it just buying the upper and bolting it on my lower? Gear ratio is 1.5.
Motor specs - 650ft/lbs - just over 700hp. Now, I boat at 6800 feet in elevation so with power losses is more like 530 ft/lbs and 600 hp.

Check this pic from back when at this post.
When to upgrade the Bravo 1? 570hp/640ftlbs - Offshoreonly.com

No steel bearing tower in regular Bravo, 1" VS 1 1/4" vertical shaft depending on serial #, on and on.

Yes you can get a Mercruiser Bravo1 upper conversion kit to install in your older Bravo1 upper housing.

input shaft bearings and retainer are bigger in an x. You will need to get a complete x or xr upper.

Batmeat,

Call All American Drive Service and talk to George. He can set you up with an XZ conversion that is about as strong as the XR without the HP leeching straight cut gears. He says it's good for 700HP for at least 200hrs, and offers a two year warranty.

Thanks. Brad.

Just be prepared for months of not having a drive and excuse after excuse of why it isn't done.

Knot,

Yeah. It’s definitely an “off-season” endeavor. George is suffering the same supply chain issues we all are.

Thanks. Brad.

Yes and no. Buddy just got his drive back 2 weeks ago after dropping it off in October. Had to relentlessly hound him and either got no response or if he got a response it was another excuse. This was a stock rebuild and a small skeg repair. Drive was returned without the skeg being repaired which he farms out. Another buddy went thru same thing last year and his rebuild didn't last a full season. Ended up buying a new drive from a local shop. Isn't even going to bother to get him to honor his warranty as the autopsy by our local Merc tech showed suspect parts/workmanship.

After I used George in 2017 to rebuild my drive I recommended him to 5 other guys on my old dock if they needed drive repair/rebuilds. At that time, there were no supply issues but I had to hound him relentlessly as well as he never met any of his promised dates. At that time he only burned me by about 6 weeks so I thought hey, we can live with that if the end product is good. His excuse at that time was the inability to source gear sets (he stocks no parts, orders everything per drive). I called him up and said hey, BAM has multiple sets I'll overnight a set to you and he lost his sh!t! But it worked and next thing you know he had the gears and finally got my drive done. I sold that boat in 2019 and know the new owner and that drive is still going strong. A couple other guys within the next couple years after my experienced used him for some of his Stage builds and again, long missed promised delivery dates but in the end, their drives are still going strong. But after the last 2 rebuild experiences from guys from my old dock I would not recommend him to anyone in good conscious. You know things are amiss when in conversations with him on missed dates/promises he brings up how many times he's been sued and brags on his win/loss record. Buyer beware.

Why not just install a Bravo1 thick floor gear conversion into your older housing, I have done many of these conversions.

253,

Do tell. What are the returns on the thick floor gears over the stock ones. How much HP/torque insurance do they provide? Are the gears really the weak point in these drives? For some reason, I always thought it was the down shaft. Please set me straight.

Thanks. Brad.