M3: thanks. i am fighting to get as much bearing at the foundation as i can, and was thinking 8' would be helpful for that , but a real minimum. i think my dad's are 8', and we used to get a '65 suburban through them, but man you had to watch the mirrors like a hawk. resale is a concern, too, but not high on my priority list. that'll be a problem for my sons, not me.