Best timing ?

Wazup guys , can anyone tell me at what degrees is the best timing in a 240z with compresion ratio of 10.5.1 with a 290 , 495 lift . Right now it's a 17 degrees (stock Static ignition timing ), the vacuum advance does not work do to the the vacuum , now should I run at the stock timing or what will be the best timing for the setup the I have ?

Thanks in advance .....