In my serv.man. it says: (page EM20) it should be on 11:25 hour and smaller bow-shape should be facing towards the front.. so.. it looks good!
Why a engine does not run perfect, there are a lot of reasons.. change the sparkplugs or the wiring or the distributor, use fresh fuel.. these days the fuel can be the problem as there is some E10 in it and cause misfires? lots of reasons...
Distributor and ignition coil original or aftermarket (junk? oeps...😢) Old contacts or no contacts but aftermarket eh... "replacements"?
Yeah, i'm a fan of original ignition.. with contacts.. as i'm driving only 1-2,000 km a year.. last year i renewed the contacts on my 240z after over 20000km.. was still good but replaced them.