28 front crossmember install advice

[charles=fla]

i am going to remove a 28 ,cut down ,front crossmember, and install a good one, the type where the front of motor bolts to cross member..any advise on how to do the job, and what to look out for..im afraid the frame rails will go "bong" and i will loose alighment??..can i do it with the motor in car, and fenders removed, and front end removed?..i hate to wind up with model a yard art...)..thanks ..charles..