Without proper alignment equipment it is all guesstimate. You can get it close by adding shim to area mentioned, camber will move only slightly but toe will have to be rechecked. Before you do any thing swap front tyres side to side if pull varies it is tyres if not it is alingment. Rear wheel drive should have some toe in, rolling motion causes them to toe out. You can make track guage out of old bonnet tow mirrors substituting four inch nails for mirrors. scribe line around centre of tyre and measure as close to centre as you can, then keep close eye on wear pattern, that will tell you a lot. Camber and toe affect wear caster does not. Regards Jack McIntyre.