Assuming the car is for street use, maybe has auto trany or highway axle gear ratio...
The Holley street dominator is a single plane intake manifold. If any of my first sentence is true the single plane intake will absolutely kill low speed torque.
I had a 340 duster with auto trany and 3.23 axle gears. I tried a single plane intake. What a mistake...turned the car into a dead dog for street use. Ended up putting the OEM dual plane intake back on and sold the single plane.
The 340 cast iron intake is a very good intake manifold. The best dual plane aluminum intakes gain very little in performance. Look for an Edelbrock LD-340 aluminum intake if you want the weight savings.