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
The 273 heads would need a flow bench so you could Port them and make sure they flow in that 220 CFM range basically get them worked up to a stock 360 head but higher velocity.
It will shut off at 5,ooo rpm with most cams for the app...because of the heads small port volume to stroke.
It will do what you want....make big low end and not rev high.

Engle has a fast rate 204/216 .479 lift 112 or 114