You will find the casting number high on the block just under the cylinder head deck or along the top of the trans mount flange on the right side
In 2002, the new 2F1E block casting had "X" shaped reinforcements on both sides, one more bolt hole on the passenger side for a sensor. The 3F1E block that replaced it in 2003 appears to be the same. As long as you are swapping a vulcan to vulcan you should have no problem. If you intend to use the ax4n trans you will need to swap out everything rather than plug a hole for a sensor.
Here is some detailed information on the 3.0 engine
F5DE is the casting number for the first generation of the 3.0L Duratec. There have been reports of an F7DE block, however I have never been able to locate one. In any case, it would be identical.
XW4E - AE, AG is the casting number for 1999 only because it's the only XW block with a 12mm det sensor boss. It has a provision for the oil feed to the right side cylinder head (Figure 4) to use with variable valve timing (VVT) although it's not being used. There are also coolant port changes that occurred on the right side that required a new design head gasket. A coolant port flange with two bolt holes can be found on the top of the block used in the Lincoln LS and Mazda MPV. This flange is plugged for all other applications. This block now has two bolt holes in the trans mount flange area on the right side above the dowel (Figure 2). Typically you will find the casting number for this block in the lower area just above the bedplate. 1996 through 2000 Taurus/Sables used the same camshaft throughout.
2000-'05 Taurus/Sable, Escape/Tribute, Lincoln LS, Jaguar S & X, Mazda MPV and 6.
XW4E- BA is the casting number for 2000-'02 and you will find the casting number high on the block just under the cylinder head deck or along the top of the trans mount flange on the right side. In 2003-'05 casting number 3W4E came on the scene. I have seen Broadcast Code engines that were 2003 and 2004 and had XW4E blocks. If you're a purist I leave it to your own heart; otherwise I consider the blocks to be fully interchangeable.
In fact, the blocks are identical to the 1999 block except the det sensor now has 8mm threads. Since this is nearly identical to the det sensor situation with the 4.6L Ford, I would assume that the same companies that provide those adaptors and tooling should be able to do the same for the 3.0L Duratec.
The crankshaft position exciter ring has two different index key slots. One is for 3.0L Taurus/Sable with the position sensor on the right side of the engine, and one is used for the Escape/Tribute, which has the crankshaft position sensor on the left side of the engine. The pistons with the four-valve reliefs may be used as the one piston for all remanufacturing applications from 1996 to 2005.
2001-'04 Taurus/Sable RFF Valvetrain
As with the 2000 models, the right head is c/n YF1E and left head is c/n YL8E. These heads still have 3 oval intake ports, but now have a rear water pump driven by the left intake cam. The right side cylinder head has a protruding ear to cover the oiling port for VVT, which is not being used.
Ford 3.0 engine
The block was changed again to a XF1E-DD casting that had one major difference: the threads in the deck were slightly recessed and the head bolts were an inch longer so they extended further down into the block. Using the longer bolts helped minimize bore distortion which improved ring sealing and reduced oil consumption. Less oil consumption meant less oil contamination, so the catalytic converter lasted longer, and that's what really mattered to Ford, because it helped them comply with the extended emissions warranty required by the EPA.
There was another new short block in 2002. The new 2F1E block casting had "X" shaped reinforcements on both sides, one more bolt hole on the passenger side for a sensor and a revised piston, too. The new pistons had a small dome on top for more compression, the oil grooves were only 3.0mm wide, and the pistons were a few grams lighter, too. The 3F1E block that replaced it in 2003 appears to be the same.
There have been only two crankshafts used in the 3.0L motor since 1986:
The original E6AE crank with four counterweights - two in the front and two in the back - was used up through '94.
A new casting that had an additional, narrow counterweight in the middle of the crank was introduced in '95 and has been used ever since. The original crank with the extra counterweight was a F58E-AA casting, but there have also been F5DE and XF1E-AA/DD castings with the fifth counterweight that are very similar and completely interchangeable. We expected that the XF1E-AA/DD would be slightly different because it came with the lighter pistons that were used in the 2002-'03 engines, but it checked out the same as the others on the balancer, so it can be used in any motor after '95, too.
There have been two different castings used in the 3.0L, but they're both the same so they can be interchanged without any problems. Look for a rod with either an E6AE or a F7DE casting number on it.
Ford has used four different pistons in these engines according to my parts book. The actual part number used varies by year and application, starting with the F5DZ-EA and going to the F5DZ-A and the Y2UZ-EA before ending with the 2F1Z-AA that came out in '02.
Our best take on it is that the F5DZ-EA and F5DZ-A are pretty much the same, the Y2UZ-EA that was used for some applications from 1999 to 2001 looked the same, but it had the 3.0mm oil ring groove, and the 2F1Z-AA that was introduced in '02 was an all new design. It had the 3.0mm oil grooves, but it was about 10 grams lighter and had a small dome on the top so it made a little more compression. In order to simplify life, most rebuilders we talked to are using the early piston with the 4.0mm oil rings up through '01, and the later, lighter piston with the 3.0mm oil groove for everything from '02 and up, but it's up to each shop to decide which combination to use year by year.
The 3.0L engine came with a flat tappet cam from '86 through '91. Ford switched to a roller cam in '92 for all the cars and trucks except the Probe. Since then, there have been eight different roller cams used for these engines, but they're usually grouped into three different applications (see the application chart at the bottom of this page for more information).
The identification number is XXXXX stamped or etched on the back of the back journal.
Rumor has it that some rebuilders have consolidated most of the car and truck cams, and that might just work, because there's only a 2º difference in the lobe centerline between most of them. But, no matter what you decide to do otherwise, make sure that you never use the cam for the Tempo/Topaz with A/T for anything else because there's a 13-1/2º difference in the lobe centerline between the F23Z-A / F33Z-A cams that were used in the Tempo/Topaz and the F2DZ-A and F3DZ-C that were found in the cars and vans during the same years.