974 heads... flow numbers

The reason why I ask is , I have. Sets of 974s ,051s even 302s and the 920s
I am trying to get the most "bang for buck" with my 273. I know the chambers are
larger on all of these heads compared to the 920s I can cheat some of the cc's with
A thinner head gasket using one of the other heads. I have been told that between flow and compression ,flow will give more power Over compression.
And I can belive that to a point.

my engine has a overbore of .060 ,not liking that at all but its is what it
Is. Thinking of sleeving the block back down to a STD. Bore size.and us the 4bbl piston
Want to run the .284, .528 mopar purple shaft with a 800 TQ. And
The torquer340 manifold . 904 trans with a "loose"converter.
4:30 gears and 26in tires.... down the line put my 4speed in "missing a few parts
For the manual right now".
Can anyone give me any ideas?
Or if I am way off base here point me in a betterDirection .:prayer: