The hybrid motors came out inthe last of the EL's. they were using AU gear.
Beehive valve springs, different conrods, pistons, rocker ratio change(2:1 old, 1.8:1 new) Main bearing caps have lumps on the sides for the AU sump side bolts, and they have a main bearing cap girdle/brace.
There is probably more differences, but this is what i remember of the top of my head.

ok heres 1, im doin a head gasket on mine, i got a change over head from jmm, they gave me a hybrid head, and when i went to return mine today they sed its a ef style (94 i think). they gave me the hybrid rocker gear so that will fit on the hybrid head. will the timing be out if i put it together as i normaly would because the head on it before wasnt hybrid???