Ignition timing - Carb+ Single Distributor 308

That sounds about right. Today's gas and carbs tend to want a little different tune, sometimes an idle jet change helps.
Making sure the distributor advance is working properly is a must. That takes a distributor testing machine. I use a restored Sun machine (1972) to set up and test distributors. Getting the distributor to return the advance is important. It will high idle if the weights are not letting the advance come back down. That is where the distributor machine saves a lot of time.

 

From your 155/78 OM:

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but the distributor advance graph on page 74 shows the total advance at 5000 engine RPM = 34 deg BTDC (6 deg BTDC static + 2*14 deg more advance from the distributor at 2500 distributor RPM).

Here's a link to a pdf copy of your 155/78 OM:

https://www.dropbox.com/s/fgpfc3cehs68vy3/MUM_308GtbGts 155_78.pdf?dl=0

 

Steve,

I don't understand the math/designation of "16*30" and "2*14". I'm sure it's not actually math (ie, 480 and 28 degrees, respectively), but - how is that interpreted?

 

The scan isn't great (and the degree symbol is placed a little low), but that's actually "16 degrees 30 arc minutes" in the Ferrari table = the distributor advance is 16.5 distributor degrees at 3000 RPM of the distributor = adds 33 degrees of crankshaft advance to the engine at 6000 crankshaft RPM -- so the total crankshaft advance at 6000 crankshaft RPM is 6+33 = 39 degrees BTDC.

By the 2*14, I was trying to say "two times fourteen degrees advance of the distributor = 28 degrees advance at the crankshaft". The distributor advance is 14 distributor degrees at 2500 RPM of the distributor (from the graph on page 74) so the total crankshaft advance at 5000 crankshaft RPM is (6+28) = 34 degrees BTDC

 

Aha. That makes it far more clear. Thanks!