I thought they only used the 4's when you ran boxes. I kept my X demesion exactly the same as it was with the #2s the boat handled great and ran 106mph with the tired 650s. I also had props that were a tad under pitched and at that speed I was at 6000 as the motors are hitting the limiters. I got props with 2 inches more pitch and the motors are fresh Im hoping to pick up a little speed despite the extra weight from the #3s. We will see.

i dont see what the difference is in a 3 or 4 i been told about a couple chris cats with 3s running faster than mine with 4s but im still figuring mine out and tuning. what x deminion are you running without boxes? im 4.25 above with boxes. are you getting any porpusing and what speeds?

If your not running boxes your x demension should be lower. I was talking to greencard about his x and he is 3/4" above the bottom with 3s. Both of our boats are 7% prop slip which is good. Mine is 1/2" above the bottom. I havent run the boat this year with the 3s yet. But last year with the 2s I had no porpose at any speed unless my drives were trimed in to tight than she would hop at higher speed. If you are running boxes I dont no what the optimal x would be but greencard said he had some friends with that combo I would ask him. What power are you running? Let me know how you make out.

Cody,,a #4 is always faster then a#3 if instaled correctly,,,the #4 has way less drag then the 3 or any other drive exept the 6 !!!!!

4.25 sound low to me thogh !!!!

Jeff also does 3/4 above with a #3 should be 1" +

I went from IIs to IIIs on my chris cat.
Speed went up a couple mph. They IIIs are a little longer than the IIs and the X dimension was set with the propshaft about 1" above the bottom, higher than my IIs were at.

Hey Jeff, could you take a photo of the rear bottom of your boat, I wold like to see were your last step is located.

Thanks,
MSW

Chris Cat project
 

Jeff, Very nice project. Thanks for sharing in your "work in progress". Pics are appreciated. My project is located over on marineperformancetechtalk.com Good luck.

Any updates??? I need a fix man!!!! LOL. Keep the updates and lots of pics coming!

things are moving along pretty well!

:worthless_without_p