I'd try to find some arneson 7ad's,held up great on a 38' formula w/ about 1k hp.

Are X power's still being made?

I dont have any person experience (yet) but for 1000 HP id go the surface drive route. Arnesons would be a speed boost over a traditional drive and not have to run the engines so hard. I dont know how affordable #8's are but Ive seen #6 selling for about $30K

This.

I've run multiple seasons with SSM 5s just under 1100hp / side in a heavy boat. Only reason I would switch to 6s is for parts availability. Find a boat with the drives already on them, will really set you forward in the project.

ASD8s are an options too. EVERYTHING breaks, nothing is bullet proof.

Also, go with good transmissions. The big BAM 1300 or 1500s. I've been thru about 5 trans so far. (One was my fault on install).

Problem with arnesons is Rik might take your money and not send you a thing, and when you need parts , good luck with that too.

Rick is just involved with the arneson 6 and 7m bravo conversions if I'm correct. The real 8s and up are a totally different company. Rik wimp vs Howard arneson

I believe the 7s are under rated for this application anyways. you'd really have to step up to an 8. Even then, when you get into the gear ratios the torque number drops off from 1k. Does anyone rig a boat with a 10? Or maybe there's a "heavy duty" version of the 8.

I thought the10s were into cruiser and diesel territory. but I haven't looked into those in a long time when I learned the +$50K in pars for Arnesons over my #5s. At that point I was still trying to control costs of my project. (couldn't afford it anyway)

we see you never miss a chance to be his #1 hater, please tell everyone what he took from you again or are you just continuing to be what’s wrong with OSO?

Mercury came out with the 8 when they came out with the new 1050, don't know how comfortable I am with 6's behind 1000+. I'm surprised the SCX and B-Max were ruled out so quickly, good to know. I'm now considering the 860 with 6's. I think in a Velocity hull that should easily get 120 with a solid 60+ cruise speed. Arneson's are definitely out, you get more control with a typical outdrive. I like to go boating regardless of what the water is doing our season is short enough to waste time sitting on the beach because is it's too wavy. I actually had the most fun taking my 280 out in 8' waves, now that was a blast. Wish I had that on video.

Right now there is a 39 stag Velocity project with 1075's, boxes and number 6 drives being completed. That should give you a idea of what one will run.