Frame upgrades 68 Dart

My car has a complete cage, but in regards to chassis mods, we welded in 2x3 square tubing as frame connectors after cutting a channel into the floorpan then welding it the full length. It makes for a nice, stiff foundation for the cage but you may have an issue with seat mounts depending on what seats you use. We also welded in a large, thick washer at the A-arm mounting holes to reinforce those points in the event of wheelstands & to simply add strength to 40+ year old sheetmetal. The "snout bars" or front runners for the 'cage are welded to the shock mounts for extra strength and are outside the engine compartment to provide more room & give a stock appearance to the engine bay.