Hello everyone,
I have a 1998 xlt with a 4.6. She has 299,000 miles her, doesn't leak oil, no smoking until this. Looking for some advice ,What other parts should I be replacing while I have the heads off? I'm kind of concerned with the high mileage and screwing something up. Any insight would greatly be appreciated.

 

How much oil is it burning? Resurface heads, valve job, new timing chain, etc.

 

It's hardly burning any oil, so new timing chains?

 

when I replaced my head gaskets (5.4L same motor essentially) you will need new torque to yield head bolts, you can't re-use them... you would be inviting trouble.
Since the front cover has to come off anyway a new timing set is a good idea, especially with that high mileage (mine had 225,000 and I didn't know if the chains were ever replaced so I did them)
I also replaced the water pump, idler pulleys, tensioner, belt, and radiator (mine had a leak)

All of those parts are "wear" parts, so spend the money while it's apart. Why risk having to take something apart again.

Be prepared to find you'll have to replace something else, I ended up replacing the drivers exhaust manifold and heat riser tube because mine was rusted too bad to re-use. I also had to put new studs on the passenger side manifold where the crossover connects.
That's my 2 cents anyway

 

Thank you very much. That all sounds like a good idea

 

Oh, I also bought a complete upper and lower fel-pro gasket set (use any brand you like that's just what I used) even if you don't use them all it's just more cost effective and you have them if it turns out you need them.

 

Thank you

 

My son in law blew a head gasket in his 98 4.6 at 170k miles - the shop said the timing set looked good so he didn't change it to save him some money. 5k later the chain broke. The shop had to eat a pretty hefty parts bill to redo everything.

I'd recommend you send the heads out to a machine shop and have them rebuilt.

 

Thank you!