At one time when there were no real good single plane manifolds avalable. A Tunnel ram was the only choice for a high RPM engine. Now that we have access to Intakes like the super victor. A tunnel ram has vary little use ,On the drag strip were you don't care about bottom end power a Tunnel ram will make good top end power . I have seen a well built Roller Cam 302 with an edelbrock torquer and 750 Dp, on a Dyno it stoped making power at 6600 rpm the intake just quite flowing. We replaced the intake and carb with two 650 dubble pumpers on a tunnel ram. The power jumped 100 hp and the engine made peek power at 8800 rpm . Tunnel rams do work in the right application, street use is not were you want a tunnel ram .