  We explore the Classical Regge Growth conjecture (CRG) in the 4d effective
field theory that results from compactifying $D$-dimensional General Relativity
on a compact, Ricci-flat manifold. While the higher dimensional description is
given in terms of pure Einstein gravity and the conjecture is automatically
satisfied, it imposes several non-trivial constraints in the 4d spectrum.
Namely, there must be either none or an infinite number of massive spin-2
modes, and the mass ratio between consecutive KK spin-2 replicas is bounded by
the 4d coupling constants.
