Order of installation

Thanks. The underside of my car is kind of a grainy, flat black color with body color overspray along the rockers/quarter pinch welds and at the pinch weld for the tranny tunnel. So that is what I intend to replicate. While I do not intend to construct a show car, I want to do things correctly. The next two projects on the docket (yeah, I am plannign that far ahead!) are going to be worthy of that detail, so this in an educational process for me.
For your project, I would put the engine in last. The engine doesn't take up a lot of space and for as long as you are going to have to wrestle the car around the garage with body pressure, no sense adding the extra 500lbs to the load until you have to. Good luck. L8r