I am putting in a 540 with about 600 HP In a Baja Hammer which has a factory adverstised weight of 2,900 pounds. Will the stock coupler handle the torque? I know the Bravo is marginal, but I am hoping that not hammering it out of the hole and avoiding wave hopping will allow it to live. I have been running a 468 with about 500 hp through this combination without issue.

I ran 600hp thru a standard coupler on my 27 with no problem. Alignment and grease is your friend.

If you are putting a new engine in then I would a new one in. Get the Hp type which has no rubber.

They all have rubber. You need it to absorb the shock of going in and out of gear. Without it, you would eventually tear up the whole drivetrain. There are 2 trains of thought.....The aluminum coupler dissipates heat faster but is not as strong. The steel one with the extended snout is stronger but holds in more heat. The few steels ones I have used have eventually had the rubber fail. I use the aluminum one. Check yours thoroughly for wear. Look at the rubber good for any cracks. Look at the splines for any signs of wear. If it looks good, lube it up and run it.
I do not use any of Mercs lube products(oil, trim fluid, p/s fluid, etc), but I do believe in their spline grease. It is some really good stuff. I also use their gear lube. Hope this helps, Eddie.

Thanks guys. I appreciate the input.

better think about installing wings on your boat! This thing is gonna fly!!!!

I had George form Performance Marine in Fox lake align my new 540.
He mentioned that the stock coupler would be a weak link in my new set up. Also he mentioned the longer snout actually holds the grease in place longer. I went with his advice. My goal is to be as close to bulletproof as possible.

How are the teeth on the splines and how old is the coupler???
If the teeth are at all sharp and not squared off, replace it or if its more than 5 years old, replace it.

I used the steel long snout when I replaced mine on my 550hp 28 Pantera.