Timing

[Hrvoje-ZD]

I am owner of a 1971 1302L beetle that has AS 1600cm3 engine from a T2 Baywindow bus.The engine is completely stock except 30 PICT-3 carburettor(1300cm3 engine) and electronic distributor with double vacuum unit from T3 Vanagon(Type 4 engine).Here in Europe we can not anymore buy gasoline that has less than 95 octane.The only available gasoline are with 95 and 98 octane.Do I need to change timing on my beetle because of that??Should I go in advance or retard it and how much degrees?