High torque 360 LA build camshaft recommendations

A friend wants me to build a 360 La for his Ram truck. It is a work truck always loaded and pulling a loaded trailer. He is interested in as much torque as possible.
Years ago I put together a 350 SBC with the early small valve " power pack' (triangle on the front of the head) heads. With a small Sig Erson cam. It pulled very strongly but was all done at 5000 rpm.
I have a set of 67 273 heads and was thinking of putting them on the 360.
Cams have changed over years, what would you recommend for a cam ?
Mid 70's 360 la probably around 8:1 compression
Stock tranny and converter
3.54 axle
About 28 tires
Stock single exhaust with catalytic conv
Thermoquad on factory iron intake