[dagnabbitt]

Your motor mounts could very well be in backwards, that would push your whole drivetrain back a couple inches. Just yesterday my buddy found out that he's been driving his Pontiac around like that for a year. He always wondered why the distributor was hitting the firewall.

Does it look like you have a LOT of room between the fan and the radiator? You should be able to fit tall valve covers on these trucks.