906 head capabilities?

I know not a lot about this engine. It was a buddy’s who used to race it. I was told it’s a 400 stroked to a 470. He swapped his whole setup and sold this short block to another guy who bought these heads but never ran the motor. I acquired it. My own stupidity, it’s not like a SBC or Import motors I’ve worked on. This is definitely more motor than I’ve handled and am now realizing the precision it needs. I know the pushrod tunnels have been clearanced in the heads. The heads have been off an I have never noticed any kind of contact on either the piston of valves until now when the spring and retainer came off the valve.
What about the rest of the dart ? Trans , converter, gearing , weight ?