1999 7.4 310 hp to a 2003 Vortech 496 425 hp
 

What needs to be done to the boat to do this swap?

How much speed do you think it will pick up an a 24 stepped v?

ttt

I do not think that you will need to do much except to deal with the new exhaust that you will likely want. I am of course assuming that both of your motors are full dressed motors. To know how much faster we would need to know what your boat is and what not. Give us more info and I am sure we can help ya out.

I went from a '98 7.4MPI 310hp to a 502MPI 415hp MAG motor and picked up about 9 to 10mph and tons of midrange power.

That was on a '98 Formula 252LS with a non stepped 22 degree V bottom, heavy boat.

I think the 496MAG's exhaust manifolds are spaced a bit wider appart than the 454/502 motors.

Go for it, good luck.

Jamal

The 496 is not dressed. I will need to add:
1.Injectors, and Module
2.Spark Plugs
3.Computer
4.Throttle Body
5.Fuel Injection Harness
6.Engine Harness
7.Exhaust

Any idea's on where I can find these "pre-owned" ?

How is it you have a Vortech without:
1.Injectors, and Module
2.Spark Plugs
3.Computer
4.Throttle Body
5.Fuel Injection Harness
6.Engine Harness
7.Exhaust

Wouldn't that just be a 496 with xxxHP ... well, I guess it prolly has Vortech heads.

Heh, just put a carb on it....it'll still blow that 310 away!
I believe arizona speed&marine carries some of those
parts. www.azspeed.com

friend with 99 checkmate zt240 454 310....gps 62mph
friend with 2002 zt240 496 375 hp 71 mph gps