Engines for the US market before 1971 (and a few 1971 vehicles) were solid lifter, high compression engines. All Manta/Ascona engines were SUPPOSED to be low compression engines, but a few have slipped by otherwise (rare). So basically all 1971-1975 US-spec engines are lower compression engines with hydraulic cams. Stay away from late 1972-1975 heads, they are prone to crack. Also, some 1974 and all 1975 blocks used cast connecting rods instead of forged rods like the earlier engines, so these should be avoided for performance use.
Bob