Chevy 5.3 head replacement

benXJ

Well-Known Member
Joined
Dec 5, 2005
Location
Raleigh NC
I'm in the middle of replacing the heads (862 casting) on a 2000 5.3, due to the head on the driver side cracking and mixing coolant and oil.

Anyone have any clear and concise writeups/tips/torque specs for this job?

Where should I get new heads? I've looked at Ebay (The cylinder head shop), HeadsOnly.com (cylinder heads int'l) so far. Anyone ever used these places? How would I know I'm getting cylinder heads that are not prone to the cracking issue of the earlier trucks?

Also, this was under the intake manifold.....should this piece of foam be there?
 

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@RenegadeT swapped heads on the 5.3 in his Burb a couple of years ago due to the same problem.
 
You should be able to pick up some heads off Facebook or craigslist pretty easy. If you want checked and surfaced heads your gonna have to spend some more money.

The foam piece is to just keep junk off the valley cover and knock sensors.


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yea...saw some on craigslist, but don't trust them. Very few people remove the cylinder heads for fun. Who knows what is wrong with them, cracked, warped, any number of things.

Was thinking about getting the 'cheaper' rebuilt ones and having a machine shop check them out for decking and other inconsistencies. Good idea?
 
I’d check some local speed shops for some used heads. I replaced a few sets for this when I was tech, it’s pretty straight forward. You should be able to find all your torque specs on the intro web. Rockauto actually carries some pretty well priced gasket sets.
 
Very common problem, defective castings, coolant passes thru porosity into the oil. I picked up my 2001 suburban with "blown heads" for dirt cheap from family friend. I found over on LStech.com, people do take factory heads off for fun. I took a leap of faith and , after a quick phone call to the seller, PayPaled like 200 bucks for like new heads he was replacing with aftermarket heads. I cleaned my engine up good, bolted new to me heads on, 4yrs 40kmiles ago.
 
The 706 heads were the ones that were constantly cracking from bad castings, but it happens to 862s too. It's just not nearly as common.

You'd need to stay with 862s unless you want to tune the truck afterwards. They're the small intake valve and small combustion chamber heads.

If you wanted to toss some 243/799 heads on it, you'd be shed of the casting issues all together and the slightly larger combustion chamber would be negated by the higher flowing intake side...and a little bit of tuning.

You're really overthinking the used heads thing though. Buy some, maybe get them surfaced,clean them real good, and bolt them on! I've had three different sets on my truck. Not the first one went to the machine shop.
 
I've got 862 heads. Driver side is messed up. Want to replace stock for stock. No tuning.

I don't want to buy heads that are cracked like the ones that came off, obviously. Is the defect always super obvious to the naked eye? How would I know if used ones I get won't crack in 100 miles? If I buy used ones and they turn out to be cracked, can they be fixed? Not to mention dealing with Craigslist and Facebook crazies.
Not really over thinking it.. there are many ways to buy replacement heads with no documented guaranteed (as much as it can be) way to avoid future problems. Don't want to do this job again.
Sure, some people replace LS heads, but the vast majority of the tens of millions that are produced spend their time shuttling kids to school in Tahoe's and suburbans until they wear out or break. I'll keep looking at options, and check out the shops mentioned.

Thanks

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benXJ said:
So what heads did you use? Any other issues when doing the repair?

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I paid $180 shipped for a factory set of heads, 862 casting. I believe this is the ad I replied to...
LS1 heads and intakes - LS1TECH - Camaro and Firebird Forum Discussion

No real issues that I rememeber...take it apart, clean it up, put it back together. Of course that's simply put, I took my time over a few weeks, no rush to get it up and running. This is the first time I worked on a GM product since carburetors went away, had to run to parts store to get the collar tool for fuel line removal. Bought a bunch of new gaskets; head, oil pan, intake/exhaust, probably valve covers. I was really impressed with GM serviceability, only had a few metric nut/bolt head sizes throughout the entire process. If this was a Jeep, I would've had every socket from 6mm to up 3/4" plus a few torx head.
 
You’d be surprised the number of people changing heads around. That are building budget drag cars. There was a guy in Asheville selling heads cheap he had a whole wall with racks at his shop full. I wouldn’t be to scared to buy a set of takeoff heads from someone.


Edit : did a quick search on Facebook for a set that had been cleaned up and checked for 250

And a set for 100 fresh off the motor

And a couple sets between those prices.

Either price isn’t much, changing a head isn’t really that bad at all. Pull intake, coils, cover, headbolts, new head gasket and reverse what you did.

On my buddies race truck we could change heads in about an hour.

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Oh crap, I see you already have 862 heads. I thought I did my research 3yrs ago, 862's were supposed to be OK, dunno. Been working alright for me, knock on wood...
 
yea...862. The driver side is jacked up. Globs of coolant/oil mixture under the valve cover and good bit of sludge in the oil pan.

changing the heads while still in the truck is pain, that is no question. unhooking hoses, clips, bolts with terrible access, spark plug wires that won't come off, manifolds that are in the way, everything is brittle, bolts that haven't been touched in 20 years and many miles, costs of gaskets, oils, coolant, cleaners, then re torquing everything, setting the rockers up, banging fingers and cutting hands all up. Then pray it runs ok when its all back together. this is when it's a perfect 70 degree low humidity day, which it never is.

This is not a job anyone would want to gamble on.

Thanks for the lead on the prices.
 
benXJ said:
yea...862. The driver side is jacked up. Globs of coolant/oil mixture under the valve cover and good bit of sludge in the oil pan.

changing the heads while still in the truck is pain, that is no question. unhooking hoses, clips, bolts with terrible access, spark plug wires that won't come off, manifolds that are in the way, everything is brittle, bolts that haven't been touched in 20 years and many miles, costs of gaskets, oils, coolant, cleaners, then re torquing everything, setting the rockers up, banging fingers and cutting hands all up. Then pray it runs ok when its all back together. this is when it's a perfect 70 degree low humidity day, which it never is.

This is not a job anyone would want to gamble on.

Thanks for the lead on the prices.
Click to expand...

I gambled, and think I came out on the win side of things. Granted it was late October when I did this, pretty much everyday was a perfect 70 degree low humidity day, I got lucky there. I did do it all outside though without a garage.
My burb was a soccer mom driven 2wheel drive with 167,000 miles, 14yrs old. There were no real oh sh!t moment with broken bolts, etc. I did find a missing exhaust manifold bolt, think I picked up a new set for more than I would've like to pay at Advance Auto.
I'm kind of anal about torque spec's, so I just googled it all as I reassembled. I wasn't rocket science. The biggest cheat I did was reusing head-bolts, and put away my engineering degree and bolt stretch studies.
 
RenegadeT said:
The biggest cheat I did was reusing head-bolts, and put away my engineering degree and bolt stretch studies.
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Probably one of the cheapest parts of the whole job...it's like 34 bucks for a full set :lol:

benXJ said:
changing the heads while still in the truck is pain, that is no question. unhooking hoses, clips, bolts with terrible access, spark plug wires that won't come off, manifolds that are in the way, everything is brittle, bolts that haven't been touched in 20 years and many miles, costs of gaskets, oils, coolant, cleaners, then re torquing everything, setting the rockers up, banging fingers and cutting hands all up. Then pray it runs ok when its all back together.
Click to expand...

It's realllllly not as bad as you're thinking it's going to be. Sure, my chest hurt from leaning over the core support, but I was good after a few days. I can't thinking of any bolts that were particularly difficult to access or any super special tools that I needed to get to them either...the rear most spark plugs or coil bracket bolts were probably the biggest pains.

There's literally no setup to the rockers though. Drop them in, bolt them down, and torque to 22 ft/lbs. That's one of the easiest parts!

The only really specific torque sequence is the one for the head bolts and then I use a paint pen and a calibrated eyeball to get the extra 50 degrees or whatever on the outside head bolts. I just start in the middle and work my way out on the intake manifold.

For what it's worth...my 99 Silverado had a 4.8 with 862s on it. Close to 200,000 miles on it before I did a 6.0 swap and I never worried for a second about having a head issue. So long as there's no Castech symbol and they check out good, I'd roll with them.

The most aggravating part of the whole job to me is draining the coolant. I freaking hate antifreeze.
 
Oooh and it'd be the perfect time to replace the lifters if they've ever given you any noise!
 
Brother in law had the same problem on his 05 farm truck. GM sells a tablet that is designed for this problem which they say is a porous casting problem. He dropped a couple in the radiator 2-3 years ago and hasnt lost a drop of antifreeze since. YRMV
 
FYI you can buy the exact same thing at O'Reilly's by barsleak. Lots of cars and trucks come with some or something similar from the assembly line.

Gm used to recommend using them on crate engines. It's not supposed to clog up anything and it's basically ginger if I recall correctly.

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LBZ_Duramax said:
Brother in law had the same problem on his 05 farm truck. GM sells a tablet that is designed for this problem which they say is a porous casting problem. He dropped a couple in the radiator 2-3 years ago and hasnt lost a drop of antifreeze since. YRMV
Click to expand...

Definitely had 706 heads on that jewel.
 
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