Won't find anything in the junk yards. 3.55s are the most popular. Well -If you can find a newer ford explorer you may luck out with 4.10s for the rear 8.8 and if you can find a f250 with a dana 50 you might find 4.10s for your front. I ended up getting my 4.10s off of eBay.
Since on the topic of gears, would a 3.73 rear end off a F-250 fit in place of my 3.55's? And how about limited slip? If I egt that, would I need a new rear end altogether, or can I make the 3.73 a limted slip?