Distributor Over-Advancing

At 150psi you are right on the predicted pressure.
If my internet sources are right, about the cam, the dot to dot method may actually get you close to the designed Ica of 64*.... because the keyway on the cam may have been put in the right place to make it easy to install, on the stock cam. Again, I don't actually know that what I was told is true.
But if I had a 5.2 Magnum,in a lightweight performance car, capable of reliably reving to 6000, I would be ripping the front off and putting a degree-wheel on it,to find out; because 19psi, and a 27point VP difference, is a massive, massive, change. It's so massive, I doubt I could run that cam in my 367 combo,as the pressure would rise to 200psi.
There is a slight downside to this cam advancement; the powerstroke falls from an excessively high (probably done for fuel-economy), extraction number of 127*, to a more-normal number of 114*. This does not make it a gas-hog; (99* makes a gas-hog,lol). In an A-body, 114 can still get into the 20's; your results will vary,lol.
So what you get is; more torque, more power, a snappier more eager to go engine, and in all likelyhood, more mpgs in steady-state cruise.
The new effective overlap of 36* will like headers for a little power increase.