Back in the day ....SCCA suspension rules allowed : replacing OEM with any material attached to stock mounting points AND any additional suspension components you wished to add ! I campaigned A Datsun 1200 in C-Sedan with Teflon rear leafs , Zeed for tire clearance and a 4 link with adjustable coil-overs front and back .Since the 1200 was basically a BMC knock-off , we used dual "SU" side-draft carbs , tuned headers, roller cam ,dry sump ,and got 150 hp to the rear wheels @ 8000 rpm . Yes we did grenade a few engines in the process, but we sure gave those " Mini"s a run for the money !