I know 1000hp is possible all day with a 1071. I know 1100hp is asking a bit much of a 1071. So what i take of it is big cube is better. Im leaning towards bigger bore shorter stroke.

JJ your box is full

I've done 565's and the best I got was 1050
They were not very reliable due to sensitivity to fuel octane

4.600 bore
4.25 stroke
Dart CNC 355 heads
Solid roller 262/272 .714 lift
8.6 static compression
BDS 10-71
Lee intercooler
2 1000 cfm 4150 carbs Tried every carb known to man !!!!!
Daytona sensor ignition with map sensor ( best thing I ever did)
11 % over drive 8 lbs boost
Jessel timing
Jessel shaft rockers
Piston oilers
904 lifters
Steff oil pan
Bryant Crank
Carilllo rods
The best HP they made on a steady state pull was 1051, but on a sweep the were 1030. So in reality they are 1000 HP . That's the most your going to
Make on pump gas. You can put a killer tune up for the purpose of seeing a
Big number on the Dyno but it's never going run and last in the boat. Please don't take any of this as negitivity about your build ,but I've spent more money than I'd ever admit trying to squeeze 1100 from these engines and from what I learned there's just limit to 10-71 and pump gas.
PS I've also tried changing compression ratio vs boost levels and there was never a real difference

Some pretty good advice and well given. Just curious if ftn is a step or not and what kind of speeds you got with it with your builds.

Your avitar not real clear but now that I look it appears newer ftn. Only asking cause I'm doing 555 sc builds for a 12 meter. 8.25:1 comp builds.

My boat is a poker run edition , yes it has the most current step bottom . With my current engines with 1150 hp tune I ran 156 mph
With the previous engines 146 mph

Good info thank you! Im good with a 1000. Just trying to reuse the 1071s without jumping to 1471s. I see you went with a shorter stroke on your 565.

Emptied my in box.

I like the 4.375" stroke the best I think it's the best combination without side loading the pistons too
Much . Also seems to be a good tq to HP ratio with 4.375. I like the 4.25 stroke for lighter faster boats because they seem to rev higher and you have better prop/ gear ratio options with higher rev engines . Some guys like big engines spinning them slower making BIG tq then turn a big pitch prop. My experience is that a prop turning faster works better on a cat or very fast Vee

I don't blame you. Where abouts you located?

The 4.375 is what I'm shooting for. There's an interesting pair of 1671s from the alex and ani boat for sale. Definitely a pair of power makers but just to big I think. Located in Mass.

16-71 would be too big for your application . Blower sizing is important to
Make a combination work. Stick with the 10-71 , with 572 ci , 8.5 compression and 7 lbs of boost you'll make a legit 1000 hp with 900 plus ft lbs torque . You will probably see 1050-1070 on the Dyno.