Custom Lower Radiator Supports for sale

I am considering putting a set on my drag car that has the inner fenders removed and frame rail / shock tower supported by a bar going to the firewall. I suppose it would be a good idea to be sure the frame rails themselves are straight and parallel before putting these on. How does a person check for that?

I think that it would be a good idea to tie the front frame rails together. I would get the car on a level floor on jack stands supported by the frame rails and start comparing measurements to the floor side to side. What if it's not level in the front end are you going to cut one of your bars?