Stearing shaft

ok i just put a new rack and pinion in my 1990 mustang, i got rid of the old one and now the stearing shaft does not reach the stearing comum in the Rack and pinion, i must have got rid of that part that was there, its power stearing, if you could let me know what i need that would be great thanks. i think i need a u joint i think not sure tho but also there is so many differnect sizes on summit thanks again.