Two words of advice: Hydraulic Steering.

I've setup quite a few Crownline 225s. It takes a lot of HP to get them to run 70 gps. More than an HP500. Do not remove the hooks. It will porpoise really bad(trust me on that). A Sternjack works really well on that hull if you could find one. I built a 750+ HP whipplecharged engine for one customer with a 225 BR. We installed a Sternjack, IMCO drive, and hydraulic steering. The best speed this boat ever saw was 81 under ideal conditions, consistently 75ish. To my knowledge that is the fastest Crownline ever built. I will say they handle very well at 70+(on smooth water). There are a couple with Raylar 496's that run mid 60s. Done a couple with 600+ HP big blocks that would break 70, and of course Clay's whipplecharged 502 that ran a consistent 70.

Bob Lloyd

The 225 BR weight was 3500 lbs, had a 18 degree deadrise with rounded edge short depth strakes and somewhat rounded chine edges. Their boats were best constructed from 1995 up to about 2002 or 2004 after that it was down hill for them as they filed bankruptcy twice around 2007 or 08 and another year. From late 2006 their boats were getting poorer quality from the factory.

Also the 225 model Crownline had a max rated hp of 425 in the 2000 years and it was 415 hp in the 1990 years. Being in the boat business putting above those max rated hp numbers you very well can be opening yourself up for a lawsuit especially if something was to happen to boat and or persons. Again I am talking about a boat dealer or boat business modifying any boat above its max hp rating. I am not talking about the boat owner hot rodding his own boat. The liability is then on the owner.

The largest dealer for 11 years running was in Dallas who sold 150 to 350 Crownlines per year. I have been in more Crownlines than I can even count. IMO the transom and the stringers / lagged bolted motor mounts of a 225 Crownline production boat over time would not hold up with high hp & torque levels than what they are maxed rated for. These boats were made for fairly smooth waters and MPH #'s under 70 period no matter how slice it up.

I would take a look at the bottom and sharpen all the rounded blunt strakes and blunt chines and sharpen the edge of transom to hull bottom if you are trying to make it run. Also the cuddy version of the 225 was 400 to 500 lbs heavier than the 225 open bow version same year to same year. The extra weight was in the cabin.

I have a single ram system laying around, I might toss it on.

Guy at the local lake had a 540 in his 225. I believe it ran low 70's. Go to Youtube under ryan00tj and there are a few vids of us running.

Happy now?

Trust me, I know Crownlines and yours will be evil handling (at best) with as much power as you're talking about. The last thing you need with evil handling is crap steering. (Kind of like an ugly girl - with bad breath.) Go ahead and install it before you even toss in the new motor. If you don't, your test ride may be your last ride. We'd kind of like to hear back from you.

I have a 94 225 CCR that I stroked the 454 to a 496. It pushes 575 hp and 650 lb/ft. I'm currently running a 26p labbed bravo 1 prop that will push the old girl right to 70 just over 5300 rpm. That's a GPS 70 as the stock speedo just rolls back around to 15-20 mph... I can tell you that you don't want to hang it out there for long. I'm looking for hydraulic steering and k-planes, anything past low 60's and it really isn't safe right now. The nice part is cruising at 45 just over 3k.

Im hoping to hit the 70 mark GPS

A stock HP500 probably won't hit 70... I wouldn't build a 500 replica, either. Merc left a lot on the table, power wise, and I don't like the combo they used. A big block with rectangle port heads and a single plane intake manifold that is only rated at 500hp can only mean 1 of 2 things. Either they won't let it wind out, and you get no intake velocity, hence the low hp number, or they were limited by the exhaust and used an insufficient cam and it can't wind out and make any power.