I am installing new ignition system tonight. Any advice on setting up the ignition advance? How much and when?

Here is what I know

502 shortblock with a pretty big hydraulic roller blower cam (dont know the specs)
Flat top forged pistons
Everything from here down is brand new.
Dart Pro 1 heads 3 with Dielectric Coating
B&M megablower all rebuilt at The Blowershop with their front snout and drive. 20% overdriven (should be 6-8lbs boost)
Intercooler with sand strainer
Hardin Marine max volt distributor
Hardin Marine Max Volt Ignition Box
Hardin Marine "Hurricane exhaust system"
Quickfuel Marine Carburetors
Holly blue pump regulated to 7lbs pressure
Bravo XR drive
Signature 4 blade 28 pitch prop

I would run the dist locked(no advance) set timing 28-32, the full advance at idle will clean the idle up a lot...with low compression should not be deal starting with a good gear drive starter, if it does, I would run a start retard thru a MSD box or a stand alone one..Rob

I tried the MSD start retard and it was horrible, I run 10:1 with a stock Mercury starter and no problems, this is my second season. I am running a pretty big cam and cranking pressure is reduced, I get the motor turning before I pump the throttle. Running a locked distributor is the only way to go with a big cam. I can idle for hours without a problem at 700-800rpm.

I'd lock the timing at 32. Much better idle. I'd consider getting rid of the holley blue fuel pump. They aren't known to be very reliable.

+ 1

I'm locked at 34* no starting issues

yea,my blue holley dumped on me two weeks ago.lucky I had ice in the cooler to cool the pos off.i did get back to the dock though.