Just changed the carb on my 1600 GT to a 32/36 Weber. Got it stared eventually and it runs very well. Ticks over smoothly and picks up quickly when I blip the throttle. Only query I have is over the timing. When I put a timing gun on it (vacuum pipe disconnected) it look as if it's about 30 degrees BTDC. The marks of the crankcase are 12, 10, 8 and 6. The timing on mine is about an inch past 12 degrees!! Is that right?

i wouldnt think you would be able to start it with 30 degrees of advance
what rpm are you idling at
might be worth finding tdc by removing a plug and see if it corresponds to your pulley
ive had it in the past where the pulley wasnt the right one

Haven't got a rev counter fitted at the moment but it's idling at about 900rpm and very smoothly. It originally had a single barreled carb and that timing was at 10 degrees BTDC which I believe was about right so the pulley is right. Also, I did check that tdc was correct when I originally timed it with the old carb. Very strange.