Well.......After nearly all day, I've finally gotten rid of the really bad idle and the back firing.
As I have stated in another thread, the distributor clamp bolt turned out to be loose, allowing the thing to turn at will.
The only thing that was holding it from spinning out of control, was the spark plug leads.
God knows how long it's been like that, as I've been having trouble with the damn thing for ages.
It must have just got progressively looser over a while, thus throwing the timing out gradually over time.
To do up the distributor clamp bolt without a Crows Foot Spanner, was a task in its self.
I had to cut a 14mm spanner in half, just so as I could get to it.
It's set at TDC at the moment, so the idle sits a bit too high, but when it's backed off, timed right and the idle's set, she'll be all good.
Anyway, It has a new cap, rotor and 9mm Eagle eliminator leads.