on a 496 is there anyway to reduce the throttle sound ,you know that sucking sound when you give her?

YES, There is a small filter type piece that is called a muffler. It is a merc. part and your local shop can tell you where it goes. They come out alot and get sucked into the motor.

any pics or part numbers,thanks

IAC muffler will help at idle. Part #5.
http://www.mercruiserparts.com/Show_...le%2DShift+%29

The intake "whistle" under throttle is usually caused by the spark arrestor. Some are worse than others. My motors have a slight whistle around 1800 rpms than dissapear after that. I friend has a serious whistle around cruise speed, 3100 rpm's that drives him nuts. You can try fiddling with the arrestor or replacing it. A K&N filter might help too.

At idle, it is usually the IAC muffler as posted. Try replacing it or making sure it is in place.

I tossed my IAC muffler. Too many stories of them causing problems. No real difference in noise. I did go to a K&N filter and it does a respectable job of cutting down the whistle I used to get at 3,000 RPM.