replacing chassis rails with box section

[steel]

as per my v8 manta thread the chassis rails are real bad mot patch on mot patch the full length from under front seats to the front panel new rails are £500 a side i thought of making my own from 50 x50 box section or similaire the problem i haveis the bulkhead is not flat but curved where the rail sits

[steel]

pics showing shape on chassis around bulkhead area and forward to front panel unfortunately not as easy as using straight pieces

[envoy cdx]

Make templates and make the box section(s) from flat metal, cut / bend to shape, or stencil them out, cut bits out individually and weld into the box section you want then fit to the chassis.