29' w/ 600 HP
 

Could a single step break the 80 mark with this combo?

I think there were 10-12 of them built at the factory 85-87 mph

I'm just kicking some ideas around, nothing serious.

The 575SCi 29 Fevers' ran 81 - 83 mph. I've seen two different serial number Performance Reports for 29's with 600's and they were right at 83 mph. Those were the one's with the anchor locker and ladder, and they were heavier than the earlier stepped hull 29's by a couple of hundred pounds.

I was thinking about building my 500EFI into something a little more. I have seen various threads with people getting 600+ from rebuilding the 500's, like I said just kicking the idea around.

29 Fever easily can reach 80+ with 600 sci with no problem!!!

My 05 29 with 575sci and scx/sc drive runs 80+ and is bullet proof. (for sale in the classifieds) I would worry about your drive with 600hp.

600sci with Bravo XR is bulletproof as well.
I had this combo 5 years no motor or drive issues.

The boat can get there if you're mapped correctly with a 525 and the conditions are optimal.
Over 80 you better make certain you're on top of the tabs & trim.

With the last prop I tested I got my 29 with with an Ilmor 625 to do 81mph and that's with 27 prop slip. We're still trying to get it dialed when I have time but I'm still hoping for at least 85 or so.