You are asking for trouble. The geometry for the steering needs to be spot on where it is supposed to be. Otherwise you won't be able to safely steer it. I bought a 49 with a FatMan front end and the idiot had moved the position of the rack. Only solution to the extreme bump steer above 25 mph was to remove the rack and mount it with the proper mounting brackets from FatMan. Before fixing the car was hair raising to drive even at 25mph! Every bump I hit caused a wild jerk in the steering without changing the steering wheel to one side or another, into oncoming traffic or in the ditch. Rack was less than one inch from where it was supposed to be. IMHO if you want rack and pinion, get a mustang II front end and a modern motor.
"Bump Steer is when your wheels steer themselves without input from the steering wheel. The undesirable steering is caused by bumps in the track interacting with improper length or angle of your suspension and steering linkages."
http://www.longacreracing.com/techni...aspx?item=8162