Should I use only SI units of measurements in review papers? I am writing a review paper and I came across a literature in which measurement of force is given in pounds and likewise for other quantities. In all the other papers, only the SI system of units is followed. Should I use the units used by the author or should I convert the measurement values to SI units?
To avoid confusion and to ensure the comparability of the results, you should use uniform and consistent units throughout the paper. You can write a note explaining that in the original paper the authors used pounds, furlong per fortnight etc.

And of course, yes, use the SI units. Nowadays all non-SI units are defined in terms of SI units. However, don't trust random sources for the conversion factors: an up-to-date and recommended source for conversion factors is the NIST Guide to the SI, Appendix B: Conversion Factors.