So I bought this 99 f250 6.8 auto 4x4 about a year ago. I bought it with a blown engine (rod punched hole in the block) as a project truck, and have finally got a replacement engine. The replacement is a 00 6.8 with just under 120K miles on it. I have never been a fan of junkyard motors simply because you have no idea how much life is left in them. Here are my questions

Are there any compatibility issues between a 99 and 00 6.8?

What can I do as part of an inspection to make sure the engine isn't junk? I was planning on getting an oil analysis and pulling the pan to look for loose rods etc...

Are there any upgrades or known problems I should fix while it's out of the truck?

Thanks in advance for your help!

 

Theres nothing major different you might need to swap a few things from your old motor but not many. I'd do a compression test and slap her in. Oil analysis isn't a bad idea gives you an idea how it was treated. Should be fine though modulars are 300k motors if you take care of them. If v10s break exhaust manifolds bolts like 5.4s do I'd get some new manifolds and bolts in while its out.

 

They do I was going to suggest putting in the stainless exhaust manifold studs while it was out too. The 00 motor will also have pi heads where as you're 99 doesn't

 

Thanks for the info. Would it be worth it to put some headers on it? I have to keep the emissions intact since it'll be tested.

 

If you want to do it now is the time.

 

Put new spark plugs in it before you install it. Since the mod motors are at risk of breaking, sometimes requiring cylinder head removal, do them now. Exhaust manifolds as well (already mentioned). At a minimum, change the bolts.

 

Once it's in, get a tune. Your '99 PCM is configured for an engine that doesn't flow well. You'll gain about 30HP and 25 ft.lbs. with the proper PI tune.

 

Is this something I could download and push to the ecu, or do I need to have someone retune it? I've replaced computers, and read codes but never changed the tune.

 

Thank you all for the input! Spark plugs are definitely on the list to replace, and after reading some threads on plugs i'm probably just going to go with some champion platinums.. maybe Iridium?? I had also considered some MSD COPs but the budget probably wont allow it anyway.

With 120K on the engine is there anything i could/should do with the injectors while its out(replace/clean/rebuild)

Mike189677 I'm assuming this is what you're talking about?

Since the entire engine is easily accessible very easily now I'd like to do any services that will be a complete knuckle busting pain in the butt once its in.

 

Stick with the OEM coils. Mod motors haven't had good luck with aftermarket COPs.

 

I would stick with Motorcraft/OEM plugs. Mine had 120K on them and were worn out, but still working fine. Lightly apply anti-seize to the plug threads of the new ones.

 

That is only true for the 2005- early 2008 3v modular engines. The 99-2004 2v engines do not have spark plug breakage issues.

 

......but they do have potential 'blow out' issues. Change them and absolutely follow Ford's procedure, including their torque figure.