Good morning Jan
( does it make a big difference to advance the timing )
A very simple question to be so complicated to try answer .
I have had several older motors with distributor and points that did not make a lot of difference on the advance . However on v-8 doges in the 90s it is like night and day . With no advance on my dakota I would expect to reach about 95 klh , with timing advance I can get up to around 135 klh for short distances . ( no shortage of power but don’t want to overheat the gasifier )
There are several threads on this subject but most are in the premium section . Here is one I found in the general discussion .