  We investigate the transition form factors between nucleon and $\Delta$(1232)
particles by using a covariant quark-spectator-diquark field theory model in
(3+1) dimensions. Performing a light-front calculation in parallel with the
manifestly covariant calculation in light-front helicity basis, we examine the
light-front zero-mode contribution to the helicity components of light-front
good ("+") current matrix elements. Choosing the light-front gauge
($\epsilon^+_{h=\pm}=0$) with circular polarization in Drell-Yan-West frame, we
find that only the helicity components $({1\over 2}, {1\over 2})$ and $({1\over
2},-{1\over 2})$ of the good current receive the zero-mode contribution. Taking
into account the zero-mode, we find the prescription independence in obtaining
the light-front solution of form factors from any three helicity matrix
elements with smeared light-front wavefunctions. The angular condition, which
guarantees the full covariance of different schemes, is recovered.
