Whipple model mx 422, 2003 year. 7.75 bottom pulley 3.25 top pulley. How many pounds will this give me? I am looking for 6lbs... Thanks.

Correct me if I'm wrong but I think it depends on the flow of your engine, cam ect... Why don't you install a boost gage for your own peace of mind?

i was going to say the same, boost is just a measure of backpressure on the motor... the more effecient the motor (ie heads, cam, intake, exhaust) the less boost your are going to see with the same setup... is this wrong?

That's correct.
Whipple should be able to ball-park you if you give them you engine info. You will want to install a boost guage if you haven't already.

Thats what I thought but I just wanted to get a rough starting place. This is a lt1 350 install and whipple doesnt make one for this motor. I will post a picture of how we made it modifying the intake!

Diameters are relative to the ratio, Just like on the roots style with teeth. I would call Dustin he should give you an idea as to the drive ratio,=Boost

Whipple will make any intake you want, they made one for me to fit the dart pro 1 heads for a sbc.