I have built a DA7600 36H rear and a 32H front so can only vouch for those specific combinations. On track wheels the front and rear spoke lengths are usually the same, but its always good to check with a spoke calc anyway.
I just checked for you using my spreadsheet that i've used for all the builds listed above and get 276mm for both front and rear 3x lacing 36H.
I have built a DA7600 36H rear and a 32H front so can only vouch for those specific combinations. On track wheels the front and rear spoke lengths are usually the same, but its always good to check with a spoke calc anyway.
I just checked for you using my spreadsheet that i've used for all the builds listed above and get 276mm for both front and rear 3x lacing 36H.
Hope that helps ;-)