I am doing the S10 Chassis swap for budget reasons. Without lowering spindles and lower blocks it actually sets about stock height But you could loose a couple inches of depth from your bed. as I anticipate I will. They are all correct in saying that the chassis swap is more time consuming. Look at the YouTube video in my signature and several other videos I have there on the swap. This might give you an idea of what you are in store for with the chassis swap. If money was not an issue for me I would go with a MII IFS. It just wasn't something I could do budget wise.
Here is something else that might help you
http://67-72chevytrucks.com/vboard/s...d.php?t=604588