A 2e dizzy is definatly the right one! I was going to suggest that you may have the timing out by 180 degrees, but if the garage timed it correctly then I suppose you can rule that out (if you trust the garage enough). You can check if each HT lead is firing if you remove it from the plug (1@ a time) and earth it to the engine whilst you get someone to turn over the ignition. Also, have you done anything else whilst you've had the engine out, ie fit a new clutch?