So I am wondering since none of the manuals mention it, is there a procedure for removing the cam pulley alignment keys prior to or after taking off the pulley?
Or do I just use a puller to take the pulleys right off?

This is my first post and I could use come encouragement as I try to discover why cylinder #6 reads literally 0 psi on a compression check. (All others are at 190 psi +/- 4 psi) I think someone has done work to this before, as those readings are higher than normal.
I have a 94 limited, black 5 speed. I love it. I will probably love it more when it runs on all 6 cylinders.

I have the intake plenum, power steering pump, and timing belt covers off, the radiator is also removed.
Please help if you can!

 

are you refering to the woodruff key? is so, then im pretty sure you will have to remove the pullies first, however im not sure exactly what you are refering to, so maybe someone else would know better than i. i think there is a very good chance that the reason you get no pressure on #6 is most likely due to a burnt exhaust valve, pretty common on these engines, and from what ive heard, almost always happens on cylinder 6.

 

Probably a bad valve. Stupid exhaust crossover. Headers might make the problem go away, if you want the truck long term. I understand that staying on top of the valve adjustments will help a great deal if you want to stay stock.

You can pull the sprockets off with the key in place. In fact, that key can be very hard to get off... but so can the sprocket bolts. PB Blaster works great for rust and stubborn parts.

For info, you can put the sprockets back on as well with the key in place... at least I could on my 3.0.