Mustang II question

[55chevrolet]

I purchased a welder series MII crossmember for my truck project. One of the steps that it says to do is take a measurement off your old axle placement. This will be where you will want your spindle to be. My problem is that I am starting with a bare frame. My old frame has an 80's Pickup IFS on it. (trying to sell it and many people are asking how easy it would be to change it to MII). Does anyone have a MII crossmember on there truck that wants to share how far down the crossmember drops from the bottom of the frame to the spindle mount? also, how high the top a-arm mount is from the top of the frame?

This is a 55 Second series chevy pickup.