Outer Limits 4x4 Board

I have got a miss in my 4.6.
I removed one plug at a time and the revs dropped apart from
cylinder no. 1
Pulled plug and swapped cylinder 3 plug for cylinder 1 plug .
. Revs dropped on cylinder 3 but still not on cylinder 1
There is also an intermittent knock.
There is spark from cylinder 1 lead.
At this point I am a bit unsure of where to go next
If anyone could help please feel free to sugest something.

compression test ?
injector ?

So you've swapped the plugs and now #3 isn't working or bot #1 and 3 aren't working? May'be a dud plug.

Seems you have eliminated the plug and the lead. Do a wet and dry compression test next and see what you come up with. Do a dry test first and if the compression is OK skip the wet test.
In case you don't know what a wet test is: put a few squirts of engine oil into the cylinder and redo the compression test and if the compression comes up from the dry test then you may have ring problems. If the compression is low and doesn't come up with the above test it may have valve problems, else it may just be an injector as Popeye sugested, can they be swapped around?

Another thing to look at possibly - did the spark plug that came out of #1 look rusty? Pull a few plugs out, and have a look at the top of the pistons with a torch - look to see if the top of the piston in #1 is washed clean - if so, that would indicate a blown head gasket or leaking liner.

Commpression came up at 180
Its on carbs
Reset points
I took rocker covers off and valves working but I thought problem cylinder looked to be a little slower, but I couldn't be sure of it.
Once again I need a little guidance.

I hope it is not a slipped liner for No 1 cylinder.

I made an error earlier ,it's cylinder 2 thats the problem
but every thing else is as before.
The engine is not using coolant
Have swapped dizzy caps
, plugs, leads.
Pulled plug and started engine ,no steam, exhaust is not steemy.
Plug out of cylinder in lead sparks well.

Is there a way apart from listening to tell if the revs rise and fall from removing a plug lead ?

OK seems you have eliminated spark, compression and being a carby engine unlikely to be fuel directly associated with it.
Some sugestions:
Timing, sometimes pully can slip, physically rotate dizzy and see it clears up.

Dwell, (duration of points closed) use a dwell meter to set other than setting points gap.

Firing order, (a stab in the dark)

Intake sucking air on number 2, pour some water around number 2 inlet and see if it gets worse.
Also:
Where's the knock coming from and what type of noise is it?