I was thinking about buying a 4.0 motor and using this winter to build it up and install in the spring.

Yes my motor was rebuilt....but not by me.

If given the time and money what, how would you rebuild a land rover motor for use?

Please list the things that can be done or should be done, ie valve jobs, head porting, gasket matching, dif cam profile, increase compression, balancing?

 

I'd take it to a machine shop for a standard block prep. They should clean it, surface gasket faces, hone cylinders, and inspect it for cracks, etc.

Inspect the main bearings. If outside specified tolerances then the crank should be ground and the bearing replaced with the next oversize.

Replace all block seals.

Replace piston rings and have pistons and rods inspected.

Surface the heads.

Valve job.

Porting, polishing, and bigger valves are options that will cost a lot and provide minor benefit. The machinist I use says the stock heads look very good already and there's very little room for larger valves.

Carbon cutting valves are an option.

New OEM or high quality aftermarket cam, tappets, pushrods, rockers, and rocker shafts, and timing set.

ARP head studs with good calibrated torque wrench.

Oil pump rebuild kit.

Ceramic coated headers.

At this point it should be as good or better than new.