The DRCE 1 casting was the best of the bunch I think, ..
It was originally 4.84" bore space but the casting was made thick
enough it's now used to make 5" bore space heads.
Some Pro stock teams still use this casting over the DRCE 2, ..
of course most are trying to use a rather weak DRCE 3 casting now.
It's a raw casting, valve spacing, chamber size etc are up to the
cylinder head person building the head. CC of the as cast ports,
um, .. there really isn't any, .. it's left very small so the port designer
can move the port where ever he/she wants.
They need specific lifter locations and cam designed for them.