Speedmaster big block heads PCE281.2153 Vs. PCE281.2140 Diffs?

Outsder said
Pics look like intake side may be spaced up and require a special manifold, or an half inch cut off the mating surfaces? Anyone know from hands-on experience with these Speedmasters?

I believe they take a normal intake, but you need the "plate gasket", or drop plate (for lack of better words) to cover the valley.