I too own a 7.3 diesel and have fixed a fuel leak. If you aren't getting fuel on the ground then your leak is not bad and probably not the problem. Are you smelling that raw fuel smell or that cold exhaust smell, they can be pretty similar at startup.
The 7.3 is also well known for leaky up pipes between the exhaust manifolds and the turbo right there next to the firewall. Mine are leaky and since the intake for the cabin air system is right there next to the leaky up pipes, I will often get a big dose of cold diesel exhaust.
So if you don't find a fuel leak then consider a uppipe leak.
