Exhaust manifold replacement: what else should I do at the same time? Share some wisdom & save me some time

No it's not hard at all .yes the discs, on my "91" the large ones were 2'' AND THE SMALL ONES under the Exhaust Manifold Gasket on the Head were 3/4" . Drain coolant and simply drive a flat screw driver thru the Brass freeze Plug and pry out old plug. Clean the block opening with a wire wheel and sand paper until shinny . Put a light film of RTV Sealant on the edge of the freeze plug ( this will seal any imperfection and act as a lube for installing). Gently tap the plug with a hammer until starts and it stays in the hole by its self. then place a piece of flat stock over the plug that covers all edges of the plug, our use a large socket ( upside down) that covers the whole plug and gently tap, tap, tap, the plug into the whole, Don't Bam, Bam, Bam, the plug. set plug depth to just a hair below the chamfer on the block. this should cost around $20 Bucks....Tim
oops , I posted the wrong info.... the block expansion plugs are 1 3/4 "
 
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I decided to wait on the expansion plugs. Removing and reinstalling the manifolds wasn’t too hard and I really need to get the Jeep operational again.

Right now I’m installing the rest of the exhaust pipes. There are 4 separate pieces (down pipe, cat, muffler, tail pipe) that all slide together and clamp. Hopefully I can get all the pieces together…
 
Great to know!

Is throttle body cleaner ok for the entire manifold and fuel injectors? Brake cleaner?

It’s ok to reuse the injector O-rings?
I wouldn't.....Rule of thumb for me....If I'm "In There"...Go ahead and replace all perishable parts/gaskets/O-rings and avoid the infamous....
"Oh Crap" regrets...
 
I got it all back together; ended up reusing all the injector O-rings but there are no leaks, and now that I’ve had them out it won’t be too hard to replace them a little later.

Now there’s no tea-kettle whistling anymore!
 
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I got it all back together; ended up reusing all the injector O-rings but there are no leaks, and now that I’ve had them out it won’t be too hard to replace them a little later.

Now there’s no tea-kettle whistling anymore!
My YJ had a bad exhaust manifold gasket when I got it.

Drove it for 2 days before I couldn't take it anymore and ripped it apart. I replaced the gasket and about $450 worth of other miscellaneous parts.

Wife was like "Why are you dumping money into a car you just bought 2 days ago?" 🤪

...this was the first of many bad financial decisions related to that Jeep.

Glad you got it back together 🤘
 
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My YJ had a bad exhaust manifold gasket when I got it.

Drove it for 2 days before I couldn't take it anymore and ripped it apart. I replaced the gasket and about $450 worth of other miscellaneous parts.

Wife was like "Why are you dumping money into a car you just bought 2 days ago?" 🤪

...this was the first of many bad financial decisions related to that Jeep.

Glad you got it back together 🤘

What I've learned about Wives.......

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Replace your freeze plugs @ the bottom of the block. My rig’s started leaking antifreeze @ 225,000 miles. Freeze plug set was $60. A cheap investment while you’ve got the manifold off.
 
> Post pics as you’re going. This is next on my list and I’m a little nervous myself. I have an 89 4cyl with exhaust manifold leak

Did you replace yours?
 
I live in an apt. complex so I'm not able to do my own (major) mechanical work. I have full faith in the auto shop I've been going to for over 30 years. (The mechanic who 1st began working on my Jeep is now the owner of the shop.). It ain't cheap but like my personal doctor, I know he'll always get it right.

My primary issue was the freeze plugs (which he initially noticed were leaking). In order to replace $60. in plugs, the exhaust man. had to be pulled. So, it was a no-brainer to check it & replace the gasket. Fortunately (even w/ 230K miles on the rig) the manifold did not need to be replaced. The mechanic had the Jeep for 3 days and it wasn't cheap. Set me back $1500. But as my wife said, "better spent on your Jeep than having a blonde girl-friend that I don't know about."
 
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I didn’t really do anything special when I did mine. There’s not much on that job that removing parts gives you access to. Maybe motor mounts if those are in bad shape. If so then I’d do new mopars.
Check out Brown Dog Industries too!
 
Really?!?! Don't suppose you have the old ones to sell?
I do, they're actually brand new, never been driven on but the engine sat on them for a year or two. I can find them and send some pics when I get home if you're interested.
 
I've a buddy who's wanting a set. Not sure if the 4.0 is the same for 4.2. We'll do some checking as well.