I have mine dropped about 2" due to the fan being low on the engine, 250ci. If getting one made, going longer might help depending on the fan or shroud. If the fan doesn't pull air through it, then a longer core won't help much. Once below the filler panel air has a hard time getting to the core.
This is what I am installing,
http://www.afabcorp.com/AFCO_Dynate...Code=80147N&Category_Code=hr_rod-rad , its about 3" thick, two big cores, the aluminum will cool much better then brass and weights about 1/3 as much. Unless you are running a big block, I doubt you need the longer core.
Joe
