JR - Depending on how radical your 409's are, you should be able to get into the 70's. My 355's used to run 73-74 in my 85 Nova II. I'll have to admit, it was a handful after about 65 w/ no steering.

Do you have counter rotators ? I didn't, and when it used to come out of the water, the rear of the boat would always skip to one side slightly when you were in the 70 plus range.

Rachet, Hydraulic steering is in the plans, eventually. My 409's aren't to radical. I should be getting around 425 HP. I wish I had counter rotation. I'm spinning Alpha SS's. So I have even less in the water but they are alittle stronger than alphas. They will also give alittle more stability side to side because they have a wider profile than an alpha. Once I get them tuned they should scream. They run good, but there is more potential.

70's
 

I have Bravo's that are counter rotating. And I just purchesed hydrualic stearing. I don't know if the older syle of Nova's are heavier but I am praying that I will push at least 75 mph by GPS. I hope these engines have enough tourqe to turn 26 4 blades. I would hate to throw new engines in for a 3 mph difference.

Here is the boat. And me with a stupid hat.

The boat dry is 5200 lbs, and with 108 gallons, me, and gear, around 6200-6400 lbs.

JR- were you running stock alphas before the SSs??? If so how much of a speed gain did you see with the swap. Im running the stock alphas and my X is VERY conservative, my 3 bladers never ventilate...........Doug

Twinn29, the SS's were on the boat when I bought it so I cant say if I got any gains. But with the SS's which are about 2 inches shorter, I theoretically have a blade tip out of the water from the 10 o'clock to the 2 o'clock position.

Right now I'm spinning 22" Hydromotives. They don't really hook up all that well with my X. I'm running about 15% slip. I can also cavitate all day if I hit the throttles alittle too hard coming out of the hole. Or if I'm trimmed out just alittle. But they do handle well in turns. Next year I'm going to give a couple Mirage Plus 25's a try. I'm hoping the extra cup will help them hook up.

Jeff

Cool JR, I was aware that the SSs were two inches shorter which is alot when talking X dim. Maybe I could find a shop that would let me try a set. hmmmmm. I wouldnt want to go out and buy a set and have them not work at all.
P29 Scarab-If your listening How much shorter are your Imco's and did you get any gains with the swap alone??

Switching from big blocks to small blocks will require some re-rigging of the boat and you may have more time in it than what you think. I think you'll be alright with the small blocks, but personally, I would have modified those big blocks. It will be interesting to see your results though. Have fun.

Cubic inches is horsepower, stick with the big blocks. Put the money into the big blocks that the small blocks and conversion will cost........ultimately will be cheaper and faster

Better Ride
 

The engine change isn't just for the speed. The boat sits in the water very low in the back. I don't think that twin bb's in a 26' boat make it sit to well in the water that's alot of weight in the back.