This doesn't add up

https://cimg1.ibsrv.net/gimg/www.off...fcecbf9e6a.jpg

sorry,typo. The 19p mirage i was at 5200-5300RPM.- 54-55mph

23P prop was 4400-4600 depending on trim- 52mph

276, 282 at.006"
224,230 at.050"
.503".510" with 1.5 rockers
.537".544" with 1.6 rockers
112°

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So, 425(9:1)-450hp(10:1) capable with RPM Intake and a good tune w/dyno headers.

Difficult, but not impossible for a Quadrajet carb

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How fast are these boats with a stock 300MPI or 330hp/454 ? hat prop man/model came on boat new with what motor?

For the rest of us that don't know what the OP's model boat style and bottom looks like:.
https://cimg5.ibsrv.net/gimg/www.off...aabb467516.jpg

alright..?

Better numbers

https://cimg4.ibsrv.net/gimg/www.off...9d36edfb63.jpg

so the 23p has about 10% more slip. but now if the 23P that is currently 14-1/4" was bigger in diameter like 15.6". slip should go down....

Came out weird from a copy/paste. I fixed that post.

Great cam, for marine 383.

Maybe, lots a variables in there and slip reduction is good, but sometimes a bit more slip means higher mph. All depends on how well power is transferred from the motor to the prop to hull

My compression ratio is around 10.4CR.

JET Performance sells Stage 2 and stage 3 Quadra jets. I am thinking on purchasing one. What do you think. I also was looking at Aftermarket EFI Kits. hard to find one without O2 sensor.... Like FITECH.

STOCK 260 hp merc would say 46-50mph depending on prop.

Whoever is doing the carb. call them and give all specs of engine and boat to order,

Your compression is a little too high for my tastes. Kind of Okay for a LS motor maybe, but this is an old style 23* degree motor. Interesting. 2nd small block here this spring with that high compression.