Diesel oils have an additive package designed to deal with soot and carbon.
More so than gasoline rated oils so this is a plus for a gasifier fueled engine ( keep dirt in suspension until the filter can deal with it ).
They are also designed to deal with the heat from turbo chargers and loading of high compression engines.
But since 2007 they all have been reformulated to used less Zinc, the engines since then also have been designed to use the new oils.
Shell says their latest oils are just fine for older engines however so maybe research this on Bob the oil guy and form your own opinion.
Lead cushions the valve seats so the the valve rotors do not lap the valves into the head.
If you do not have valve rotors with old time manually adjusted valves you have nothing to really worry about.
I do like the air oiler for dry engines, some just need that to deal with NG.
Also Brad Penn oils have lots of zink in them if you want to pay that much.