Load the view from model space into the drafting pallet as you normally would. Open paper space and under Options/Space Units set the Paper Space scale to that desired - e.g., in your case 1 in = 100 in will fit the 480 inch dimension on an 8-1/2 x 11 sheet.
Only then insert your view into the paper space. When dimensioned, 480 length will now show as it should: you will likely have to resize the font, however. The rulers will remain at 8-1/2 x 11.
There's probably a more elegant solution, but this is what I use.