85 f150 351w h.o.?

[bdtznettles]

Hey guys just bought a 1985 f150 xlt lariat explorer it has a 351w h.o.,c6,& 9" rearend all factory is this a rare option package? All the f150's this era ive seen have a 302 &8.8 rear any insight into this truck would be appreciated.thinking of hopping up the truck but want to be shure i'm not ruining a rare option truck.thx

[djfllmn]

nah i think ford put the 9'' in there to handle the extra power of the 351