Don't know...I've never worked on one. Vacuum has little to no effect at cranking rpms, and it should certainly start with the vacuum hose attached.

Here's what I was able to find out for timing specifications:

TDC +/- 2 deg at Cranking rpm

Below 20 deg at Idle rpm

18 - 22 deg at 4000 rpm
Note: Without vacuum, intake air temperature sensor plug pulled off.

29 - 33 deg at 4000 rpm
Note: With vacuum, intake air tempertaure sensor plug pulled off.

Dwell 10 - 54 % or 9 - 49 degrees at Cranking rpm
30 - 60 % or 27 - 54 degrees at 4000 rpm

__________________
1989 300 SEL that mostly works, but needs TLC