Which crossmember for tko600 and lowered body mounts?

[lutzy]

Just bought a tko600 kit (69 Camaro) from a vendor and the crosmember that was included was 5/8" thick where it bolts on top of frame between the body. The problem is that the crossmember that I took out(PITA!) was only 1/4" thick I had to hammer it out. So theres no way i'll get the 5/8" one in. I knew the previous owner replaced the stock body bushings for the DSE body mounts which I think lowers the car 1/2". Im sure plenty of people have a simliar setup and would like to know what kind of crossmember you use for this application?