Header selection for an L92 6.2 in a 72 K2500

[Highcountrybulls]

Looking for some guidance on what headers will fit between the frame rails on my 72 3/4 ton 4wd. I’ve done a pile of research and found a pile of different information out there but nothing conclusive. With the outrageous shipping cost of getting goods up here to Alaska I’m trying to get the right parts the first time.
Long tubes are my first preference but I’ll settle for whatever is sure to fit.
Thanks in advance for any advice you can offer!