Narrow molecular weight distribution polyisoprenes (PI), polybutadienes (PBD), poly(isobutylenes) (PIB), poly(methylmethacrylates) (PMMA), polystyrenes (PS), and poly(octadecyl methacrylates) (PODMA) have been studied by size exclusion chromatography (SEC) in tetrahydrofuran (THF) with light scattering and viscometric detectors. The molecular weight (M) dependence of the intrinsic viscosity, [eta], and radius of gyration, R(g), is reported for THF solutions of these polymers, in many instances for the first time. The availability of these data for a series of chains of varying flexibility allows a test of the universal calibration principle in SEC. Furthermore, an apparent dependence of the hydrodynamic parameter in good solvents, Phi, on chain stiffness is observed. All chains appear to exhibit hydrodynamic draining in THF.