I have heard that the 4.6L and 5.4L engines share the same bore size, so I was wondering if all that would be necessary to convert a 4.6L to a 5.4L would be to swap cranks.

Obviously there will be breathing issues because of the cylinder heads, etc.

So will a factory 5.4L crank swap straight into the 2005 4.6L, or are the journal sizes different or differently spaced?

Thanks!

 

No can't do it the most you can get out of the 281 is about 302. Can't stroke it enough without problems. Useually it is stroked out to 300.

 

The bore is much longer in the 5.4 I don't think there is enough room for the stroke. I also think that the 3 valve heads are the same between the two engine displacements just different Variable Cam Timing.

 

The blocks aren't the same. The 5.4 has a taller deck which accounts for the longer stroke. A crank swap won't do it.

 

Thanks guys.