Batteries have been installed over the right rear for ions because of direction the engine turns. The torque tries to twist the axle the opposite way, lifting the right side and planting the left.
Some more race oriented suspensions have compensation for that effect built in.
'87, 105,000 mile stk short, SN89 Paxton 5 LBS, X303 Hds, E303, Cobra Int, 70 mm TB, 30# injrs, 1 5/8 full leng, no cats, 2 1/2 w/dumps, A5, 3.73, ET R's, Frnt Drag Eibach sprngs, Baseline Relocated upprs, HPM lwr arms, stk rear sprngs 1 coil cut, adj. struts shocks, 3150 w/dr. 1.60 11.39 118.