1969 d100

Ok guys, so tuning things up a bit, went to get new plugs and currently the truck has autolite 24s in it and the local napa said their book is calling for autolite 65s.

So what plug is this bad boy supposed to use?

NGK ZFR5N remove the crush washer if a drool tube head or NGK UR5 or UR5GP for a peanut head.