[My427stang]

Lots of variables mostly based on cylinder pressure and load (car weight and gearing) but a good rule of thumb is 36-38 total and all in by 2700 rpm

With that, I'd try two things, bump your inital up to 15 and see if it pings, if it doesnt, close enough. With your start retard, it'll certainly still start fine.

If you dont like it at 15, then time to dig in and get more advance from the distributor. On my heavier car I like 14 initial, 38 total all in by 2500-ish

Once you get that total timing squared away, I'd look at the rate. You didnt mention how quick it comes in, and Mallory typically has a pitifully slow curve. With a Cobra, I cant imagine having the full advance at anything more than 2700 and probably more like 2400-2500 depending on your cam grind.

Every Mallory I have dialed in, has full advance at 3300+ and about 20 degrees centrifugal, so my guess is that you have a lot of snap left in that motor when you get a real timing curve in

Mallory builds them so any person can drop them in and not ping, anyone that wants them to run hard, has to work the curve. BTW MSD is JUST as bad, big heavy advance springs, they leave a lot of performance on the table until you recurve them