I've put about 4,000 miles on my tubular kmember and tubular lower control arms. No problems yet with setup you see in my sig.
69 CAMARO... SBC, Yenko clone
66 Austin Healey Sprite... SBC, 200-4r
02 Z06...QS, Magnacharger MP112
93 typhoon... McCoy motor, PTE turbo, A2A