I'm thinking the plugs were a key component. Having the carb that * I * rebuilt being another factor. Not to say the other was done improper, but I have no idea either way because I didn't do it. Also, it should be noted that I am in NO WAY or claim to be a carb expert. About that 600, though, all I can say is that this car just did not like it. None of the usual tricks worked on it.
At any rate, I'm happy it's getting close to a proper tune. Just in time to mothball it for winter. Plans for this winter are to add disk brakes, and if I get really ambitious, tackle the rear end and trans.
Just when I thought everything was good, mechanical issues once more. I was out around the neighborhood driving and dialing in the carburetor, I heard a loud, singular * PING *, and the engine died immediately. Engine spins over quickly, same as before. Something in the timing set let go. That's obvious. Not sure what yet. Coolant is draining. Timing cover is coming off again. Stay tuned.
To be more specific, it looks like the cam is not flush with the front of the block. Is it possible something is off? Does the distributor drive gear help locate the cam? Or is the locating dowel on the cam sitting too far back? IIRC, that dowel sat out further when I originally installed it.
I edited this post from the original. I was angry when I wrote it, and cooler heads have prevailed since then.