440 motorhome engine

I just ran a 12.98 with my 73 motorhome 440 in a Dart. As said above, forged crank, six pac rods, windage tray. I don't know if all 213 heads are the same, but all of the exhaust manifold holes on mine go into the water jackets. Not just the two on the ends like 906 heads. Had a bit of a water leak when we first fired it up. Higher comp pistons and a good cam did the trick for me.