As has been mentioned....... with the heads having 2.25 intake valves, and not knowing if oversized seats have been installed to facilitate that...... they could be a big fan of worms.

Buying used race stuff is risky at best...... throw unknown stage 6 heads into the mix...... and the risk factor def goes up.

Perhaps there is documentation of exactly what’s been done to the heads buy the shop that did them.
They might be really nice set of heads........ but they also might have intake seats about ready to fall out.

11’s out of a Charger?
That’s just a flat top 440 with a decent cam, e street heads, an rpm intake, headers, 9.5 converter and 3.91/4.10 gears.