-> Trevor: I have no rear arms....
But longer driveshafts I would need because Iīll move my gearbox about 80-100mm to front....
Actually there is nothing special of the placement of steering rack... You must have steering rods and front control-arms in same angle, like you can see my latest picture. Then you have very little of bump-steer....which as far as I know is always present with McPherson front suspension because of itīs design. For Ackermann-steering.....itīs a bit more complicated thing to decide what to want.
I placed my steering rack slightly ahead of steering arms on spindles. (so steering rods point a bit backwards if looking on top) I found it will have effect when cornering you have your inner wheel turned a bit more than outer wheel. You got both wheels turn same angle if you place steering rack so that steering arms does not have any angle back- or forwards (= no Ackermann steering and thatīs the best (?) setting for drifting and gravel/show rallying etc for rwd car) and so on. I thought it would be best for track use to have some Ackermann and specially the one which turns inner wheel more. I donīt know if Iīm right or wrong...it finds out when I get my car to track someday.