I think the dash is completely different. Meaning you can't just put the gauges in there. I have a 70 dart. I made my own cluster to hold autometer gauges.
Here is a link to a thread I started some time ago. Great ideas in there. http://www.forabodiesonly.com/mopar/showthread.php?t=230540&highlight=Cluster
Not hard at all. Just find a set of manual collars from a member on here. Then cut off the bracket on the end of the column tube. Find all the console pieces and install.
Does the part your measuring go under the seat or up the fire wall? If that is the under seat part then the back carpet will overlap that part and it won't matter.
Has anyone purchased seat foams from "vintage auto works" (vintageautoworks.com)? I was wondering the quality and fit of the foam, if anyone has had any experience with them I would appreciate the comments.