Anyone know what the pressure side hose fitting size is on a first gen dakota 2wd.

Tried a Russle 5/8-18 to AN fitting bUt the o-ring seat is about .100" short of seating, and the threads are a bit loose. I'm connecting to a gen III hemi pump, so a factory replacment hose for the dakota is not a sure bet, and I already have the rest of the braided hose assembly. .. thanks in advance