weight reduction potential?

Hey all, planning on picking up an old UJM (likely a CB750 or CB550), and doing a cafe conversion/other restomod.I know one of the biggest gripes about these bikes compared to modern ones is how heavy they are (i've heard top heavy especially), but where exactly does this weight come from and where/how much can usually be practically shed on a cafe build? Aluminum tank, lighter exhaust, etc.? Thanks! via /r/CafeRacers https://www.reddit.com/r/CafeRacers/comments/gef8sw/weight_reduction_potential/?utm_source=ifttt