Cylinder Head Casting Numbers ?

**J7319M** · 03-19-2017

2000 Buick LeSabre w/ 3800 Series II V6.

Where can I find the casting number for the rear cylinder head ?

Please don't tell me I have to pull the rear valve cover.

**Scottydoggs** · 03-19-2017

why would you need the casting #? not thats theres a ton of info to be had off it, iirc its just got the year on it. if you need a head, any 3800 na head will work.

**GTPpower** · 03-19-2017

Yes, you have to pull the valve covers.

**J7319M** · 03-19-2017

Scottydoggs - I need the casting number to get the correct cylinder head, correct ?

GTPpower - I gotta pull the alternator and belt tensioner to get the rear valve cover off.

**Fivefingerdeathpunch** · 03-19-2017

Any cylinder head from basically 97-08 that was on a NA 3800 would bolt right on to your car.

Supercharged heads look different because the injector holes are cast into them.

**Scottydoggs** · 03-19-2017

Originally Posted by J7319M

Scottydoggs - I need the casting number to get the correct cylinder head, correct ?

GTPpower - I gotta pull the alternator and belt tensioner to get the rear valve cover off.

you'll be taking it off to change the head. like stated, any n/a head will work. whats the back story here? why the head swap?

if it hydro locked the upper intake failed and leaked coolant into the cylinders and or oil as it always does.

**J7319M** · 03-19-2017

Originally Posted by Scottydoggs

whats the back story here? why the head swap?

How much time do you have ? I was changing the intake manifold gaskets when I got the bright idea to chase the bolt holes in the cylinder heads to clean them up. Usually that's not a bad idea if a person uses the correct size tap. The correct size tap in this case would be 5/16"-18. The tap that was used by the most idiotic person in the world was an 8mm X 1.25mm. So by time I started on the third hole, I finally realized that metal shavings are not supposed to be coming out of a threaded hole if it's just being chased. So now with 3 holes in the rear head severely damaged, I order a Time-Sert kit from Amazon. That would've worked fine if I was able to drill the holes at the correct angle. Two of them I got pretty close, but one was way off. So in my vested interest to punish myself for being so stupid, I'm going to replace the rear cylinder head.

**Scottydoggs** · 03-19-2017

oh lord, thats a bad story.

be best to hit up a junk yard and snag a head off any 3800 thats na. you can grab the front head thats easier to take off, same head.

you also need new head bolts.

**Scottydoggs** · 03-19-2017

and you'll want to watch some you tube vids on valve lapping. your gonna need to do that, when cars sit the valves get rusty and pitted up, sure it will run, but it could run even better if the valves all seal like they should.

**J7319M** · 03-19-2017

I just want to find a head that's never been remanufactured. I want a head that's never had anyone attempt to repair any of the threads. I'm thinking a salvage yard is the only place to find that. Being as particular as I am, I'd go to a self pull yard and pull it myself. If I find a good one, I'll have it looked at by a machinist.

**Scottydoggs** · 03-19-2017

no one chases lim bolts in the heads, so those will be just fine, some times they are whole engines, some times they are part torn down, never know what your gonna find walking the lanes of cars.

**wowitsfast** · 03-19-2017

check this out http://www.rockauto.com/RSS/vehiclef...l=en&html=true get what you need for the swap

**J7319M** · 03-19-2017

Most of the time by time I get there, the entire engine and trans is gone. Hopefully this time I can get there there before the big parts giants get there.

Scottydoggs - do you happen to know the size of the lower intake manifold bolts ?

I know they're 5/16"-18 with a 3/8" hex flange head, but I don't know the length.

**ItHurtz** · 03-19-2017

Reuse the intake bolts, you need new HEAD bolts

**Scottydoggs** · 03-19-2017

no idea, i like his idea, snag the bolts from the jy.

**FordMan77** · 03-19-2017

Where in the USA are you? I have a head from my old 00 GP GT motor (N/A Series II) that's good. Never been messed with just pulled it off my old motor. Shipping could be an issue though if you're too far out. Has around 150K on it but never had an issue with it.

**J7319M** · 03-19-2017

FordMan77 - I'm in Clovis California. That head sounds very interesting. Why would you have just one ?

**FordMan77** · 03-20-2017

Well, technically I have both from my original motor but the #1 cyl. ate a bolt and turned it into a 5 cyl. (don't ask, lol..) I never bothered to look at the valve on that head since I needed a new motor after that anyway so I don't know what shape it is in. I just yanked the motor and replaced it then later on I pulled everything off the old motor down to the shortblock so I could scrap it. I'll look for the good head tonight if you would like, just let me know. I can ship though UPS at my work but I can't imagine it being cheap.

**J7319M** · 03-20-2017

That sounds real interesting FordMan. The salvage yard here charges $39.99 + $4.99 core charge. I haven't priced machine work yet. It would be nice if I found one that was so sweet, all it needed is cleaned up and new valve seals installed. Is there any chance you can snap a picture ? No damaged or repaired threads, correct ?