It depends on what size valves are in the heads. If it has the 1.84 intakes, you'll notice a little increase in power up to about 4500 RPM, if that high. Above that, those small valve heads just won't flow enough to take advantage of the CFM the q-jet is capable of delivering. You'll have to have a machine shop look up the casting numbers on the head to be sure about the valve size. 1.94 intakes will flow a little more and the power gain should be a little more noticeable.
[This message has been edited by Randy Mosier (edited 11-29-99).]