After all the test drives that i did I made the decision to replace my suspension with proper torsion bars:
The spring bar that i use for torsion is a flat bar spring 3 x 20mm for No1 and No7 road wheels.And for No 2 3 5 6 i cut the spring to 3 x 16mmThose leaf springs are 380mm long with a center collar that is used to preload the torsion this way i use the one spring for both sides by using 180mm of either side
Made a new exhaust muffle and relocate the battery. Since i make this major modification i also re weld all road arms by striping them first.And counter boring the flat bar and shaft by 5mm then weld .