I'm probably not calling it by the correct name, but is there an aftermarket tappet cover/cylinder head cover (plastic part w/oil cap)?

Also, would it be a really involved process to remove an oil pan off the engine or could one just slip it out after removing the bolts?

 

To the "tappet cover" yes. There are a couple of folks that do aluminum billet covers. I think Hellman's may be one, not sure.

The engine will have to be lifted some (not a whole lot) from the mounts to get the oil pan out; it won't just "slip out".

 

Just unhook the shocks from the axle and jack the truck up, no need the unbolt the motor.

 

Any websites for the tappet cover?

 

How does that create more room between the oil pan and cross member?

 

it doesn't.

still have to lift the motor

 

My thought as well.

When I did mine I pulled the valve cover, and the rockers and injectors for the two back cylinders then lifted the motor up. This gave me adequate room to remove the oil pan while leaving the pickup on.