The A-Body With A Job

I like your thinking.

Windage tray = 15 HP on the big end.
Valley pan keeps things cooler, bonus HP.
Timing chain tensioner keeps things in line and snugged up nice. Small cost, nice bennifit.

Speaking of reliablity, exhaust manifolds right?
FWIW, Comp Cams has a line of cams designed to work with exhaust maifolds. Otherwise a nice split duration cam is what you should be looking at.
Know your cruise RPm and have a cam selected to operate in that RPM. Cruise at peak torque for best mileage and throttle response on the road.

Leave the crank be, stock is fine, full groove bearings a nice plus.