The 4.10 center section should be able to bolt into your original housing if you want to keep the new Huck brakes in place. There's really no need to replace the entire axle assembly just to get the higher gear ratio. That 4.56 gear is very popular with the rock crawler crowd that runs ridiculously oversized tires, so there might be a market for it with them. They like the low ratios.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!