help!! putting a stick in an auto car

i have a 64 valiant slant6 push button car i wanted to convert it to a stick car .a friend turned me on to a compete 3 speed drivetrain out of a 65. all i had to buy was a shifter. so i have the motor back in the car bell housing on. went to put the trans in and noticed that the aftermarket shifter brackets are hitting the floor brace that the trans crossmember bolts to. do i just cut out as little as possiable to make the clearance or cut the top of the brace out and move it back. what have you guys done to make this work?