Just did that swap on my 02, I installed an 07 3.0 Vulcan from a Taurus.
A 3.0 Vulcan FWD block & heads are the same as a RWD Vulcan 3.0, There is a difference in the head gaskets,intake exhaust manifolds, & accessories etc, But they can be swapped motor to motor. You need to change the head gaskets on a FWD to the RWD gaskets if your installing it into a Ranger as the FWD motor will run hotter than normal due to the Water pump cooling route differences if you leave the FWD head gaskets in place, change gaskets & your fine. Also there are diffeneces in the heads of Flex fuel vehicles versus gas only, The later model FFV heads have beehive springs, smaller valve stems & slighty higher compression due to the chamber differences. Mine was FFV motor in the 07 & 02 & the heads were identical. In my case the local yards wanted $800 or so for a Ranger 3.0 with 90K+ miles, I bought the Taurus 3.0 with 15K for $250.
JP02XLT