Here is a list of most header manufactures that fit a 302 Maverick. This came from the Maverick web site. The list is from 2009 so some of them may be discontinued. The person who put it together did a lot of work and it's handy to see the tube and collector sizes, part numbers,no guessing.
http://mmb.maverick.to/showthread.ph...hlight=headers
Your friend might take a look at the site overall, lot's of drag racers on there (mostly bracket guys), good Maverick info.
Good Luck, Kelly