Yes they do work and for the haters, there are better manifolds out there I bet, but day in and day out, The LD4B is a great manifold. (as you well know) A friend built a fairly mild .030 over 440 with a custom grind Comp cam, warmed over stock heads, headers and a CH4B intake (like the LD4B) It made 497 horse and 520+ torque. And it fit under his fresh air hood without mods and pulls like a freight train.
