Ignition Coils 2006 4.6l V8 DG508 Vs DG511 Vs DG521. Brand Motocraft Vs AC Delco. Need Help Please!

[BCosta]

I need the forum's help with making a decision. Money tight, I'm looking for quality on budget if that makes sense.

History. Bought with 149k, accel coils replaced with a set from 1 A on here, and E3 plugs installed.
209k now. Swapped old Accell when i had a misfire. Three months later> multiple misfires.

I have a set of Motorcraft Plugs & set of AC Delco DG 508 Ready to install.

I get conflicting information when searching multiple vendor sites. Ford Site Shows DG511.
- some vendors show one part #, others show multiple part numbers fitment.
-when Searching the AC Delco DG511's on Amazon.... First Coil Comes up AC Delco DG508. (thats how i ended up with them)

I came across DG521 as fitting
-DG521 research shows same exact as DG511, but with slightly longer brown boot.

Did motor change from '06 to '08? On some sites, the DG511 show from '08-10 only.
They are also $60 bucks cheaper per set

I would like to stay with AC Delco or close to OEM. No $30 per set.
Could i use the 508's in place of 511, or use 521 as same coil(straight boot)

Thanks in advance.

 

[ThunderbirdSport]

The model year change was more to do with the spark plugs (two piece, in model year 08 they went to an updated version that doesn't break off in the head)

As far as I know, the coils themselves *should* interchange, but I wouldn't go as far as to bet my life on it....I'd wait for someone a little more sure to confirm/disprove that.