[en] A consistent set of best values of the 2200 meter/second neutron cross sections, Westcott g-factors, and fission neutron yields for ²³³U, ²³⁵U, ²³⁹Pu and ²⁴¹Pu are presented. A least squares fitting program, LSF, is used to obtain the best fit and to estimate the sensitivity of these fissile parameters to the quoted uncertainties in experimental data. The half-lives of the uranium and plutonium nuclides have been evaluated and these have been used to reassess the significant experimental data. The latest revision of the spontaneous fission neutron yield anti nu, of ²⁵²Cf and the foil thickness corrections to the fission neutron yield ratios of fissile nuclei to ²⁵²Cf are included. These lead to greater consistency in the data used for anti nu (²⁵²Cf). Similarly, the ²³⁴U half-life as revised leads to improved consistency in the ²³⁵U fission cross section. Comparison is made with the values from ENDF/B-V and other evaluations