i just installed 2 infinty ref 2-ways today in the front doors.
you take the cover for the 6x9,s and turn it upside down,(the logo facing the door with out the screen).
they screwed into the factory holes. i had to get # 10..1 1/2 inch screws to fit.
the door panel was alittle snug but it went back on with no problem.
wish i would have read this earlier , i would have taken a coupla pics.
also i dont know how much depth diff. between the ref. and kappa series.
but it should work.

 

Is there a difference between the 05's and the 06/07's? Would I have this issue in an 05?

 

I swapped out my 6x9's rather quickly, i bought these kickers that were pretty much made for the rams and they fit in the door panel and old speaker bracket with no issues, out with the old, in with the new in a couple minutes. I doubt they are the greatest, but their crap load better than the stock infinitys.
http://www.autotrucktoys.com/ram/Kic...1343C3569.aspx

 

TAMALE,
they should be the same, the 6x9's i put in my 07 came out of an 04 i had before.same as my 6.5's.