as long as you don't take the timing gear cover off(thing the oil fill is connected to) you won't have to worry about screwing up your timing. after the install you "should" get it timed to get it dialed in, but you will still be able to drive the truck just fine with lining up the timing marks on the gear cover and the IP. it is really not hard at all. just take your time and have the article that i linked to before handy and you will be good to go.