Think I've found my problem. Got car running, idle at 800rpm, timing 12 degrees. Nasty stumbly erratic idle. Vacuum gauge bouncing all over the place ( rapidly). Above idle gauge is steady. Sprayed some carb cleaner around base of carb, engine stumbled massively, also sprayed around intake manifold gaskets, engine stumbled badly , vacuum gauge went nuts bouncing between 12 and 16 . Think i got a few leaks. Suspect I'm gonna have to mill the manifold but with not knowing how much the heads have been milled I think I'm gonna have to take off a bit at a time until it looks something like.