i have a 1980 510 wagon(stanza wagon? not sure if they were available in aus) currently its bone stock but planning on zx struts if there is no brake upgrades for stanza struts? looking for big brake upgrade to fit under 15x7 or 8 with 0 offset also the car suffers from understeer pretty badly so i was thinking de arch rear leafs add a leaf. lower the front according( most likely 2 inches) fabricate a rear sway bar and maybe a thicker front sway bar. not sure on diameters for sway bar though. also what is a good starting point for stanza front spring rates ive heard 200-250lbs but not sure. does anyone know if a 225 45 15 on a 15x7 0 offset fit under stock stanza arches. if not whats the correct offset and widest set up for a stanza. Do 1600(510) lca's and tension rods fit stanzas because i have access to adjustable 1600 lca's and tension rods. thanks.

Putting a bigger, i.e thicker, front sway bar is only going to increase understeer. Put good tyres on it and then tell us if it understeers. All other things being equal, a stiffer rear bar will reduce understeer.

Dont know the answers to the other stuff.

Can get sumitomo 4 piston calipers of mid 1980s landcruisers and hillux easy enough or twin puston sumitomo off coroa and zeds too. Better imho than stock stanza ones.

where you located usa? In aus we didn't get the wagon to my knowledge