Ditto on all the advice already posted.

Way too much carb and not enough boost.

I second that....also locking the dist to no advance and running 28-30 will work well...

Timing is very dependant on the build. Compression ratio, cam, cylinder head design, etc.. Are they fast burn heads? 3 lbs of boost is not much. RPM also depends on the build. If it's a stock cast rotating assembly 4600 is not too far out of line. 30 degrees total is a decent starting point. I wouldn't run more than that unless you have all this information.

Bob
Full Throttle Marine