Fuel to use on a 250

[kolle_hond]

So I have been running my truck on LRP (lead replacement petrol) ever since I got it, but the pump where I usually fill up no longer stocks it. Here in South Africa, I have two other choices: unleaded 93 or unleaded 95 (octane levels). I have heard that in some cases a supplement is needed for older engines. Most of my engine is stock as far as I know, so will there be any risk using the unleaded? And which one would you guys recommend? I am taking a long trip to my family in the countryside (about 400km) tomorrow, and I don't want to get stuck with a engine failure somewhere.