Here's a link to a rather thorough discussion of cooling we just did a couple weeks ago, that should help you with the concepts involved. If that doesn't fully address your questions, you'll at least be able to narrow your query down. http://www.clubhotrod.com/forums/sho...=fan%2A+shroud

As to moving your engine forward, it's just not worth the effort. Dimple the firewall slightly if necessary.