any 1996-2003 4R70W or 2004 4R75W will bolt in place of your trans right now as per my knowledge. Although I think 98 and before the 4R is a 2 bolt starter which is different - so post 98 you might need a 99+ starter? I'll need confirmation on that
yeah mean the speed sensor? Mine was replaced with a new one - so im sure you can put one in a later model - but haven't dealt with that sort of thing.