In the N2 PMV, Best range speed varies from 120 to 135 Kts (depending OAT,Zp, weight). It's in section 10, level flight performances.
On the N3 PMV, no more mentioned.
Fooster, if it's the max endurance (Vy) you're after, it in the same charts (section 10), represented by the dotted line.
Agreed for the tangent, but it doesn't work on level performances, as the tq origin isn't 0 (??)
Fafe, the figures in section 2.3 (130Kts) is an IFR limitation (AFCS), not the best ratio distance/fuel. No reason to put this value (best range speed) in limitations. If it is one, will be in para 1 (Airspeed limitations), not in para 4 (IFR Flight).