The heads (untouched) on the crate 120 are far superior to the heads on the 110.
Why is that?
Let me explain so this doesn't sound like a slam of Sadunbar. Not my intention.
Those MVA heads work quite well on the 120r motor. That does not assure they would produce equally well or even decent on a 103-110" motor with 4.375 stroke with a peak rpm that we seem to see as about 5,500 rpm. My comment is based on what the motor demands and each motor, each intake tract, has to be considered for it's physical characteristics and the application. This is not a slam on the parts either they have their place and would be right at home on a 124 or 131 motor as well. I just wished they would have used bronze guides. Notice the cam that is supplied with the 120r. The timing is a little non-traditional but IMO that is purposeful as well to suit these heads and motor configuration. The dyno I provided is proof that just some blueprinting can further wake these up.