I have the radiator out.
I have access to the front of the motor.
Can I add a cam without doing anything else to the motor? No port and polish, rockers, valves etc?

What would be the minimum that I need to do?

I have added an Offenhauser 4bbl intake, EFI exhaust manifolds.

 

I believe so depending on the lift and ramp angles. Might have valve spring float if the engine is somewhat tired.

... might as well replace the timing set if it has more than 40k miles.

 

Just be aware you will also need to pull the intake manifold and the valve covers in order to replace the cam.

 

Here is a question I could answer myself if I looked, but do you have to remove the oil pan to get the timing cover off? I want to change out my timing chain being that I don't know when and if ever it has been replaced.

 

If we are talking I6 300 4.9 they use timing gears no chain. If v8 then you may have to drop the pan but it should still be doable in the truck.

 

A 4.9l is a 300-6.

My bad. Thanks for the correction... it's been a while since I rebuilt my Mustang's 200 (with the mighty, mighty one-barrel).

 

Sorry for not specifying, but I got a 390FE. I would rather not have to take the pan off, but if it can be done on the truck that is a little less discouraging to do?

 

You can pull the timing cover without pulling the pan, you just need to cut out the front oil pan gaskets on the sides, the timing cover kit should come with new pieces to fill those gaps. Make sure to use RTV in the corners to prevent leaks, and I like to use Hi-Tack on the timing cover to block gasket to help prevent intermix issues.
The intake will have to come off, the valve covers, rocker rails, pushrods, lifters and distributor as well. The lifters must be replaced when replacing the cam. They wear in together.
Replace the timing set, it's cheap and has to come off anyways. I highly recommend going with an adjustable set on the advance setting like the Comp Cams 7108. This will improve torque noticeably.