I don't understand why you want to move it that far forward. Please elaborate

I want a longer wheelbase (about 105-106) but because it is a 4runner I can't really move the rear axle much without major change. So I figured moving the axle forward about 2.5-3" and the rear axle back 1" will give me the wheelbase I want. Also moving the front axle forward will give me better clearance at the rear fender/rocker area. I know the frame narrows in front of the area you would normally insert the tube but that is why I asked. To see if maybe someone who has done an SAS could look to see if the tube could be moved forward about two inches.

Basicly I want to extend the front end of the frame about 2.5" (weld in a 2.5 x 2.5 square tube right in front of the factory crossmember) then hang the spring hanger below that. Resulting in moving the front eye forward about 2.5 - 3". Then the shackle tube would be moved forward to match. I don't want to get different springs, I already have these and I got them for a great deal. The other thing that extending the front of the frame will do isl allow me to have better clearance for a winch. If this doesn't explain I will try and draw up a diagram of what I am thinking. I just like to overthink things and see what my options could be. I just might be a little  

For what it's worth the 4Runner is an 1988