  The Fermi Large Area Telescope (LAT) has recently reported the detection of
pulsed gamma-rays from 6 young pulsars (J0631+1036, J0659+1414, J0742-2822,
J1420-6048, J1509-5850, and J1718-3825), all exhibiting single-peaked pulse
profiles (Weltevrede et al., 2010). High-quality radio polarization data are
also available for 5 of these pulsars, allowing derivation of constraints on
their viewing geometries. We obtain independent constraints on the viewing
geometries of these pulsars by using a geometric pulsar emission code to model
the Fermi LAT and radio light curves. We find fits for the magnetic inclination
and observer angles alpha and zeta with typical errors of ~ 5deg. Our results
are generally consistent with those obtained by Weltevrede et al. (2010),
although we do find differences in some cases. Our model may lastly provide a
framework to constrain the radio emission altitude.
