55-57 Chevy used that system, I raced around in those for years and never had any problem what so ever. You could actually add a cross member in there as well if you want some real support making it a 5 point system. for the front I used a 73-77 Chevelle trany cross member facing bacwards.Then I drilled the holes for the mounts into that and cut it to the correct width, finally welding plates to the sides of it so I could bolt it to the inside of the frame. It had the exact angles on it for the front mounts.
Lothar
