Most of the electrical plugs will only go on one way,so as long as you get all them hooked back up,the rest is pretty easy Ed.
You're one step ahead of me now though,the cam and header job i did on my buddies 6.4 Challenger works great,but on his 3rd pass at the track on Saturday,he sheared an axle off ,and it tore up the axle side gear bad enough i won't reuse it,and of course Ma Mopar and ZF don't sell service or replacement parts for the cars ZF diffs,they'll only sell you a complete diff,and there's none available in Canada,and only a couple available at US dealers,and they won't part with them,so we're trying to find a 3.90 geared Challenger ZF diff in a wrecking yard,and even that's not panning out great,as the 3.90 diff is only available in 5.7 and 6.4 Challengers with the 6 speed manual transmission,aarrgghh