I have a 1994 Formula Ram Air with t-tops, rebuilts transmission, lt1 with a few mods, no emissions system, granetelli MAF 58 MM TB, lt 4 cam, cat replaced with an exhaust cut out, flowmaster exhaust, now my question is at highway speed i can hear a definate Knocking speed while holding any speed if i accelerate or decelerate it goes away only while cruising and holding speed staedy it knocks... its driving my crazy