Truck pans are all rear sump. Car pans are all pretty much the same because the engines sit over the k-frame in the same location. Magnum pans and LA pans will interchange as well but use the Magnum gasket/seal if doing that if you happen find a center sump Mag (don't think any Magnums were car apps).
Mancini Racing has a great assortment of oil pans if you are looking for more capacity.