I have wondered if a Hunter 9600 Tire Balancing center could be programmed to approximately determine tire rolling resistance using the 800 lb "road load" feature?

You can determine both coefficient of aerodynamic drag and tire rolling resistance by coasting down a hill of steady and even percent grade, first at light vehicle weight, then a second time near gross vehicle weight rating.

As far as I know no one has ever tested how well a 360 V8 responds to static compression ratio changes.
The iron Magnum cylinder heads are about 62 to 65 cc "real world" and the specs on the Aluminum Magnum Mopar Performance cylinder heads are 52 to 55 cc, and maybe could be milled down 20 to 30 thousandths.

Doing a three way MPG test where two Rams or Dakotas ran a "convoy style" highway fuel economy test with 62 cc iron Magnum heads, then had one of the vehicles modified to 52 cc AL heads, then finally "ground out" enlarged chamber 75 cc iron Magnum cyl heads would be interesting.

I would guess 4% changes.