Right, im going to try and write this out as best i can,

Other day i had bad times, Turned out tappets were all out, since the i have driven about 700 miles + with no problems.
On the way back from russ' last night the problem came back after about 2 hours driving, I managed to drag the car back this time with regular stops for a cool down.

The car was ok at 60 until it got too hot then wouldnt keep aboe 60, then it got worse and worse, to then dragging right down to 15mph, couldnt even put hardly any pressure on the accelorator, it would then think about it and start to work again an start ticking normally. then stop again.

Anyway, managed to get back and went through and tried the tappets again, two sides were tight so sorted it. Didnt actually get to give it a test drive as it wont play ball, It occasinally ticks over but as soon as im giving it revs it bangs and slows down then kicks in. ?

other thing is a slight puddle of petrol ere,

have you got a timing strobe to check it? is it on 123? carb clean and free from dirt? (old metal tank?) any fuel filters fitted?

FIT YOUR DUMP TUBES!

Its on 123, would the carb being dirty affect it so badly to nearly stop?

no idea. only offering some ideas to make you and others think abit. its got oil in it right?

yeh, i learnt the hard way with the purple one.

Sounds like it's getting hot, maybe start with checking the oil cooler is clear and not caked in crap. Then check the timing is right.

I think the fuel puddle thing is simply down to the little hole in the bottom of the inlet manifold, assuming it's doing that when the car is turning over prior to starting?

mine always has a bit of fuel there... its normal. (i think)

Like Russ says, too hot will be bad! does it smell extra hot or feel it when you have to stop? and noises other than its amazing exhaust note!?

It seemed to go fine when it was 4 up going to Canterbury at full chat! when did it start to go bad?

I've you've got any dirt blocking the jets in the carbs, you'd get running issues. 123 could be playing up - try it back on points & condensor.

Is the engine cold when this happens? Maybe one of the heads are lose? Normally if a sylinderhead is lose, the engine will act like this when cold, and if the heads are not to lose, it gets ok after heating up. (Beacuse the metal expands)
Easy to check when the valve-covers are off.

Just adding "things too check" here....

Nice forum btw. Seems to be many GB people here now, but I guess it will get more international as time goes by.
I'm from Norway, so there you go; A bit more international!