designa used 3mm plate 1mm thicker than richards (2mm) all side rails are gussited inside and tubed where all holes are re-enforcing inside rails where spring hangers are welded. and rest of chassis is fullywelded, not many people realise that there is only designa that use 3mm plate for almost everything on the chassis,
if you want very strong and well made chassis then phone design chassis again, they make and alter evey asspect of chassis to suit what ever you want,how long you want, what ever engine you want,
i do know they have just done a one off 88" coil altered down to 80" wheel base,power steering and fitted in a v8 that he wanted with a 5 sp gearbox instead of the std 4 sp,