We are conducting an experimental search for spin-diffusion anisotropy in dilute 3He–4He mixtures at very high B/T (17 T, 2 mK). Previous experiments have not reached sufficiently high B/T ratios to observe the effect in very dilute mixtures, for which quantitative theoretical predictions exist. The planned experiments will require NMR experiments at very high values of the dimensionless spin rotation parameter μM. We have performed numerical simulations of the nonlinear spin dynamics to assess the feasibility of spin-wave and spin-echo experiments.