Highest flowing CFM electric fan that ACTUALLY fits?

A nice 26" 2 core radiator is how I'd roll with it. Fitment wouldn't be a problem, and I'd rather have a good 2 core radiator (with large cores) then 4 skimpy core rad. Just my 2 cents, now = .04 :D
Will a 26"fit?
I thought only the stock 22" was supposed to fit....

Jeff