Slight mis-fire when I take my foot off the gas

Hi. I've got a 1973 T2 Bay 1700 type 4 engine with automatic transmission.
I have a slight mis-fire / popping (best description I can give!) when I take my foot off the gas, after accelerating.
So far replaced coil, condenser, points, HT leads, distributor cap.
After all that she's definitely pulling better and running a bit smoother but still the same mis-fire / popping!
Any ideas?
Cheers Dobber

 

I'd look for an air or exhaust leak somewhere.

 

Cheers.. will do

 

Check your timing ad well

 

Cheers, timing too!

 

Looks like that's the favourite. Cheers

 

Maybe a touch lean,espeacially if it pops when running downhill

 

Thanks Pony. Old plugs looked a good colour so assuming okay. Cheers

 

mine was doing that yesterday. think it must be a zorst gasket. bloody new zorst too!

 

Exactly the same symptoms as mine last week. It was a leak on the manifold to head gasket. Only popped as I lifted off the gas.

 

I hadn't realised that I hadn't let everyone know what it was. Turns out it was a crack leaking air on exhaust manifold. .. welded up and running like a dream