is there a difference between either size or placement of the driver side engine mount for the v8's from an old body like 2003 to new body 06??

 

None.

 

the reason i ask is cause i have an 06' 4.6... i bought a set of headers for an 03' 5.4, cause no one makes long tubes for the new 4.6, i wan see that the flanges fit the heads, and i can actually tell that the egr tube is in the right place but since i have work this whole week, i have not had the chance to remove the stock manifolds and check clearance, but it looks like the second primary tube is going to contact the driver side mount. i guess i'm going to have to wait and see, but if you say they're the same, i dont think i shuld have a problem... thanks alot, that really gives me more confidence for this attempt

 

They should fit - There both 2 valves.

 

i know... i need to wait till i actually try them, but from what i can see physicaly, my stock driver manifold's second port sits about 3/4" above te motor mount, but the second "runner" is at the same level as te port. the second primary tube on the headers drops downabout 1 1/2" from the port. thats my main concern.
also on the pass. side, there's a semi-circular brace in the frame that sits across from the starter and ther's only like 3 1/2 or 4" between the 2, if the headers dont sit just right, i think they'll hit that brace.

like i said, i'll really have to wait and see. hopefuly they'll fit and us new body 4.6 guys can finally have some long tubs available for us, i'll let you guys know

 

ok my shops parts system says that 2003 4.6/5.4 and 2006 4.6/5.4 all use the same starter, so i know that'll clear, its just that brace

 

Passenger side - This is a 98 5.4L - Doesn't look like much room - but it fits -