55* total timing? WTH?

Morning guys.
So here are the specs:

360
318 heads ( I kow, I know... #-o )
Cam: I dont know specs anymore but it wasnt stock, and wasnt crazy. Id refer to it as an RV cam or "mild"
Stock Chrysler electronic ignition, scavenged from a 73 dart
"Chrome" ECU
Stock small block distributor

Plugs look great
Carb just rebuilt
Cap, rotor and wires in good shape

So here goes.
I got the idle set at 750 in park.

Initial timing: 15* BTDC (seems VERY high)
Vacuum Advance: 16*
Mechanical Advance: 24*
Total Advance being: 55*

Mopar performance suggests no more than 35* total timing.

At this point I have a few options.
But first its noteworthy to mention I am not so sure I believe my vibration dampener hasn't slipped and the timing mark is off... I say that only because it doesn't seem likely to run well or at least start very easily and it has been with no issues that you might expect with that much advance.

Now, the way it seems..... I need to reduce the degrees of timing by 20* total. My obvious options to get the timing down would be retard the initial to around 6*BTDC, reducing it by 9*, then the other easy option would be to reduce the vacuum advance the other 11* for a total of 20*

This, to me sounds a bit drastic! I don't care to tear into the distributor to change the mechanical advance, primarily because it is a stock unit and has probably never been toyed with, so I have no reason to believe its far off from where it should be.

My question is.... What does this tell you veteran engine guys?

I am doing all of this in order to tune this thing in, and just optimize everything.

Its worth noting that I DID, retard the timing to 6* initial timing and test drove it. It didnt seem to make much difference. Starting or otherwise... #-o

Any input is appreciated.
Thanks FABO! You guys rock!