Well I was going to move on and pick up a 04 Expedition but recent circumstances are permitting me from doing so. Anyway I'm going to throw another engine into my 99. I have found plenty of 5.4L engines but the 4.6 has been hard to come by. Now recently i have stumbled upon 2 with low miles (70k) at a killer price cause my buddy works for LKQ. My issues is this the two they have are the 8 bolt fly wheel model, but i don't know if i have a 8 bolt or a 6 bolt can any one help?? People keep saying check the VIN it will tell all but that is not the case with my truck when ever i look for parts.

 

can anyone help??? need to know ASAP

 

Check the junkyards ahead of time and see if one of them has an 8-bolt flywheel. When you pull the engine if you have have an 8-bolt you're all set. But if it's only a 6-bolt then run down and buy the 8-bolt flywheel and swap it out. Remember to get 8 new flywheel bolts.

I "think" 6-bolt flywheels were used only in the 2WD models, while 8-bolt ones were used in the 4WD models.

 

Flexplate bolt count is a non-issue with the 4.6L's used in trucks/Expys. Both of them are the correct bolt pattern for your existing torque converter. 6-bolt crankshafts are Romeo built engines,and 8-bolt crankshafts are Windsor built engines.
JL

 

I know a place with 2 8- bolt motors for decent prices on with 54k and on with 77k. So your saying they are interchangeable like that?? I can change form a 8 to a six bolt?? When i checked my Vin online it said it could have either or so thats why im wondering if i can check which it is b4 i take motor out cause this is my only transportation right now...






So are u saying the same as the other guy that the flywheels can be swapped??? Cause like i said B4 according to the dealership and the site i could have either even though i have a Windsor motor

 

No,you can't put a 6-bolt flexplate on an 8-bolt crank.Nor can you put an 8-bolt flexplate on a 6-bolt crank. But,you can use either engine-doesn't matter.As long as the engine you're getting has a flexplate on it-you're good. As long as the trans stays the same(and with a 4.6L you only get a 4R70W)-either flexplate will work with your torque converter.
JL

 

So what exactly is a flex plate? Is there a special way to install it if my truck currently has a 6 bolt and i would have to change to an 8?

 

Flexplate=auto trans "flywheel"
You DO NOT HAVE TO CHANGE THE FLEXPLATE as long as the "new" engine has one on it. The torque converters are all the same mounting pattern for 4R70W truck transmissions,and will all bolt right up to the 6-bolt or the 8-bolt flexplate.
JL

 

Thanks man just want to be sure cause my expo has been very funny about parts. I dont know why they have to make so many of the same cars and truck with out interchangeable parts.

 

Here's the thing about modular engines. There are a few minor things that are different-but many,many parts will interchange,and with minimal effort and trouble. If I were you, I'd get an '01-up 2V 4.6L from a truck or Expy and have at it. You'll need to use the intake,etc from the new engine, but all of your electronics, harness, and ignition system from the existing engine. It'll make a nice power increase and will run just fine with the original tune that's on your existing PCM.
JL

 

Make sure new motor has new flexplate/ flywheel. And u will be ok... I thought the new motors didn't bolt into the older gen expy dammmmm I'm swaping now and could have used that info

 

Engine block is the same. Bellhousing pattern is the same. Motor mount location is the same,etc,etc,etc....
The only differences are some minor intake manifold changes,and a few electronic sensors/devices. Sort it all out and it's a very minor difference that can be handled very easily. Worst part will be yanking the old and dropping in the new.
JL

 

Here is an example of a flex plate. Note the 6-bolt pattern around the center. Those are where the plate bolts to the crankshaft. The holes around the outer edge are where the plate bolts to the torque converter. A flex plate with 8 bolt holes around the center otherwise looks identical and bolts to the TC in the same way.

 

Yea tell me about it doing now

 

You didn't ask before you started.