Josh, concerning the shrinking of the hood: There are two issues here. First you have to decide if shrinking is the best way. It is possible sometimes to run a slapper over an area and accomplish what you need. My favorite way is to move the slapper around the high spot while striking the slapper with another hammer. I do doubt this is going to work well on a flat hood that is going to be very springy But I would certainly try it.
If you determine you must shrink it, there is a UTUBE Visio "Dime size heat shrinking with oxy/acetylene" In this Vidio he uses a torch but the theory is the same with a stud gun shrinking tip.
I have never owned a stud gun so I can't elaborate on that.