well a week ago or so i changed from my buddies carb to my old one (which is crap) but we tuned the carb and distributer and i drove it home but now it won't start, it is at TDC and the rotor is pointing the right direction, all the plug wires are where they are supposed to be, but it still won't start( my buddy has been telling me for a long time that the vacuum advance on the distr. is not working but that should not affect it, but do you think the whole distr. went bad, when we put my old carb on it we had to trun the timming down so i figured maybe i had to turn it back up to get it to start cold, but no matter how i turn the distr. it will not spark