Ignition timing - technical querie

[sdwells]

Hello there,
I have a 1990 230TE, and I wonder if anyone can confirm the ignition timing for this car. It's been 'modified to run on unleaded', so the sticker says, and the Haynes manual suggests 13 degrees BTDC. My local dealer says 8 degrees. Who's right?
The Haynes Manual also states that to advance the ignition, you turn it clockwise, but this appears to contradict the timing marks on the crankshaft pulley. Consequently, I'm a bit puzzled. Any help, anyone?
Regards, Steve.

 

[threepointedstar]

Ignition timing

this is the way I was taught to set these
4000 rpm vac off 27 deg btdc.I think it gives you about 10 deg btdc at idle
good luck