Have you looked to see what the distributor advance is doing?
Checked timing at the "Massimo" timing mark while revved above 3000 RPM?
Observed the stability of the ignition timing at idle?
And if they're Spanish Webers,make sure the aux venturies aren't loose in the carbs.
I have Centerline's 11.1 mm intake cam in a 1978 Sport sedan and it idles beautifully with Spica.
Also, spray around the carbs and their mountings wit carb cleaner to search for vacuum leaks. Not uncommon to find leaks between carbs and manifold/adapters.
78 Spider, Webers, header, Shankle cams, bumperless, lowered, Konis
78 Sport Sedan, header, Spica