31ss x dimension?
 

I checked the x dimension on my new to me 31ss and it is aprox. 6.5" below the hull. This seems awfully deep. Anyone have any input on what their dimension is, or what it should be for optimal performance?

Check to see how far the exhaust is tucked up under from the bottom of the swim platform. When I had my 31 (500 EFI's ) built I requested a high x-dimension. There was little to no room left between the exhaust tips and the bottom of the swim platform.

There is only 2" between the top of the exhaust pipe and the swim platform.

I thought for sure this would get some responses.

you can move your motors and drive up with out moving your exhaust tip holes, you just have to get some custom risers made that drop lower to your tips. . 6.5" below the hull is DEEP but some people like it deep it depends on who she is lol. But for real id move them up at least 4''. 2.5'' below the bottom leaves you some play room.

I am hoping to get away with using some shorty lowers. Just wanting to see what others have for an x dimension before I go out and spend the $ on them.

I try to remember to measure mine tonight. My exhaust tips are as high as possible under the swim platform without cutting the tip flanges.

My 31ss with 496 HO's is about 6.38 inches.

Thanks for the reply. It seems everyone's drives are DEEP! Hopefully someone will chime in that has used shorties or moved their drives up.

I have Alpha SS drives, CL of propshaft sits at 4" below bottom

Thanks 30ss. How does your boat run with the drives 4" below the bottom? Does the boat have any issues with prop blow out etc?

When I first got the boat it was a bear to get on plane.
I had Mirage plus 21p, took them to Hale prop and they took them to 20.2 and added some cup.
Made it much easier to get on plane and cruise efficiency is great.
50@4000 around 18-20 GPH, 63-64 @ 5400 60 GPH
I only have about 315hp a side so it's no rocket.
If I played around with props I might get more out of it, but when summer is here I'd rather be boating than tuning.

Thanks so much 30. I think I will start looking for some -3 lowers.

I just bought a 97 31ss with imco -1 drives, I will measure X dimension and let you know.

I have a 97 31ss with 2" imco shorties. runs 80 to 81 gps. yes prop blow out on take off. put on 1" spacer and it still blew out props but dropped the top end to mid 70's.