I have a 02 31 sonic with twin 496 ho's and it runs 73-74 with 28p labbed props want to get to the 80mph mark what hp would i need and do any of the engine builders out there sell bolt on kits to get me there?

The 500efi 31's run 80+. Check out Raylar. They have upgrades for the 496HO. Not cheap, though. Plus, you'd want to upgrade your drives or replace with XR's.

02 31ss with fresh 500efi , xr drives labbed 28 bravo props
79 mph

Is yours the one in the classifieds?

so basically anything over 500hp should get me 80+? onesickpantera mine is not forsale love it !!!

If you are serious about sinking money into this boat to add 8 mph, a 500 efi swap is the only way to go. There is no bolt on for a 496 that is going to get you to 80, and pulling them out and adding "kits" is not cost effective, and will not add to resale, in fact it may hinder resale.

Putting a nice set of period correct 500 efi motors in that boat would be quick, easy, and will raise the value of the boat. Plus you will have your old power to sell or store. Working the right deal on 500 efis, and selling your old power may have you out the door for $5-10k. Carbureted power can be found for even less, however I would keep the stock power to swap back if you plan on selling in the next 5 years.

Good look. Be careful, you are walking a fine line that many of us wished we had never crossed. Remember, reliability will also trump a small speed increase.

I agree with 4bus, a swap is the cheapest and easiest.

Yup, 4bus is right, even if he does own a fountian. 496HO's are great, bullet proof motors. UNTIL you F with them. Then you are replacing everything but the block to get them reliable again. A swap is most cost effective.

http://www.offshoreonly.com/forums/s...67-525scs.html

If I remember correctly, these and a pulley change can put you near 90.

I think you are thinking of 575sci's. teamsynergy runs in the 90's with turned up 575sci's!