Yes I believe you can pull the studs.
Dunno what your needs are with the truck but the 3.0 is goona get a lil better MPG, But your goona have to spin the motor to get the power outta it. 4.0 not so much. My 99 ranger has the 4.0/auto I average 5100-5200 lbs GVW. Only real complaint about the truck is I wish it was a 5spd.
Might give the Mazda's a look. Same truck just lil uglier
I would be looking at what rigs are going for locally before I even looked at KBB. For what they consider a good condition toyota pickup to be worth I would think everybody would be driving them. KBB is a joke IMO