TD42 running hot when towing

[mudski]

New nissan fan clutch fitted, blades all in good condition.
All under guard rubbers good.
Plastic air dam underneath good condition.
Some of foam strips between aircon condenser and new large radiator missing.

Get some foam and fill those gaps mate. You want to force the air through the radiator, air flow will take the easiest path and with the foam gone, a lot of air will be just going around the radiator, not through it.