Cylinder head compatibility [Archive] - GrandAmGT.com Forum

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chris_gt_74
12-12-2011, 03:32 PM
01 heads from an Alero are the same or compatible with an 05 heads? Will 01 heads work on my 05 Grand am.

[ChaosweaveR]
12-12-2011, 03:38 PM
IIRC, the LA1's head design never changed from 00-05...somebody correct me if I'm mistaken.

My initial concern would be the condition of the heads, I'd take them to a machine shop to be refinished, new valves, springs, pushrods, lifters, headgaskets, valve cover gaskets, etc. To boot, you might as well change the LIM gasket. Make sure it's the redesigned metal gaskets.

chris_gt_74
12-12-2011, 05:13 PM
Condition shouldn't be a problem but yes I will address that question. The only reason I ask really is because when I do a part search for an 01 and an 05 I get 2 different part numbers from Autozone. Now I know that may make zero difference but it is a concern I have because I don't want parts I can't install correctly. Input welcomed lol.. please.

[ChaosweaveR]
12-12-2011, 05:18 PM
Well if you're that concerned, you might as well do an LX9 top swap. WOT-Tech.com sells the parts, you'll have your NEW heads, with better flow.

chris_gt_74
12-12-2011, 05:31 PM
The heads I want to buy are the one's alerored04 has for sale. But I need to know if they will work with my 05 engine. I was considering a swap but if these will work for my motor I may go this route.

[ChaosweaveR]
12-12-2011, 05:39 PM
Oh, his heads for sale? Why not just PM him? lol

chris_gt_74
12-12-2011, 05:46 PM
;1168762']Oh, his heads for sale? Why not just PM him? lol

I have. We have a deal worked out pending I can confirm they will work with my engine. He doesn't know for sure and suggested I post here and ask if anyone may know for sure if they are compatible.

AaronGTR
12-12-2011, 08:20 PM
Pretty sure that in 2004 they changed the size of the rocker bolt from 10mm to 8mm so the threaded holes in the head are different. That year was when the 3500 was introduced in some models, and GM applied the changes across the board for "common assembly" with the 3100 and 3400, according to 60v6.com.

You'll either need to buy his rockers with the heads, or buy some separately. Otherwise, they should be identical.

chris_gt_74
12-12-2011, 08:28 PM
That's what I wanted to here! I also noticed the rocker bolt change but was unsure of any other changes. Here's another question though. Will my LIM still fit the older heads or should I use one from that year? I think the water tube on it has a screw type fitting as opposed to the 05's slip on, that is if I remember right. I searched for some good pictures and couldn't come up with any that I could do side by side but I couldn't see any real differences other than the rockers and some of the water passages being slightly different sized.

HOYS
12-12-2011, 09:23 PM
The LIM will fit the older heads.

chris_gt_74
12-12-2011, 09:37 PM
The LIM will fit the older heads.

Do you agree with AaronGTR that the rocker arms/bolts should be my only hurdle? I don't know enough about previous amendments to our engines to know and I greatly appreciate the help. I want the upgrade bad I just want to try and avoid being in a pickle trying to piece things together lol.

AaronGTR
12-13-2011, 04:36 PM
The LIM had no changes on it. Only the 3500 LIM is different because the ports on 3500 heads are different. If you are using 3400 heads, any year 3400 LIM will bolt up, and there was no change to the heater tube. ('99 LIM's had a different EGR port, but you don't need to worry about that)

HOYS
12-13-2011, 06:00 PM
Do you agree with AaronGTR that the rocker arms/bolts should be my only hurdle? I don't know enough about previous amendments to our engines to know and I greatly appreciate the help. I want the upgrade bad I just want to try and avoid being in a pickle trying to piece things together lol.

96-02 are 10mm rockers. 03+ are 8mm. I have some 8mm rockers for you if you need them, used of course.

chris_gt_74
12-13-2011, 07:38 PM
96-02 are 10mm rockers. 03+ are 8mm. I have some 8mm rockers for you if you need them, used of course.

Mine has 8mm too but I'm going to have to get 10mm one's for the heads I'm looking at.

But here's my new question. What ratio do I need for the rocker arms?

HOYS
12-13-2011, 08:11 PM
Mine has 8mm too but I'm going to have to get 10mm one's for the heads I'm looking at.

But here's my new question. What ratio do I need for the rocker arms?

I also have 10mm rockers laying around.

They are all going to be 1.6s IIRC.

chris_gt_74
12-13-2011, 08:20 PM
I also have 10mm rockers laying around.

They are all going to be 1.6s IIRC.

I was thinking it was 1.6 but did not know for sure or where to look. Are they in good shape and complete?

HOYS
12-13-2011, 08:43 PM
I was thinking it was 1.6 but did not know for sure or where to look. Are they in good shape and complete?

Pulled them from an engine myself. I think the car was under 100k and was in the yard because of a rear end collision.

I have pushrods I'll throw in but I'm not sure of their condition.

chris_gt_74
12-13-2011, 09:01 PM
Pulled them from an engine myself. I think the car was under 100k and was in the yard because of a rear end collision.

I have pushrods I'll throw in but I'm not sure of their condition.

I may need them but I'm looking at buying alerored04's stuff and it has custom pushrods for the cam but I guess if the cam does not go in right away I might need the stock pushrods unless the pushrods from my 05 will will still work with the 10mm rocker arms. I've got 90k on my engine.

HOYS
12-13-2011, 09:20 PM
I may need them but I'm looking at buying alerored04's stuff and it has custom pushrods for the cam but I guess if the cam does not go in right away I might need the stock pushrods unless the pushrods from my 05 will will still work with the 10mm rocker arms. I've got 90k on my engine.

I was just going to throw in the pushrods because I don't need them.

You should use the custom length pushrods as they are most likely in better shape and are designed for the cam.

chris_gt_74
12-13-2011, 09:42 PM
I was just going to throw in the pushrods because I don't need them.

You should use the custom length pushrods as they are most likely in better shape and are designed for the cam.

Yeah I knew I needed them for the cam. I was talking about if by some chance I don't install cam right away but I install the heads will my pushrods still work? Not saying I would go that route without doing the cam too but just to know I guess. How much would you want for the 10mm rocker assemblies?

HOYS
12-13-2011, 10:28 PM
Yeah I knew I needed them for the cam. I was talking about if by some chance I don't install cam right away but I install the heads will my pushrods still work? Not saying I would go that route without doing the cam too but just to know I guess. How much would you want for the 10mm rocker assemblies?

Pushrods are the same length to all LA1s.

I think 30+shipping (7 bucks?) is reasonable?

chris_gt_74
12-13-2011, 11:10 PM
Pushrods are the same length to all LA1s.

I think 30+shipping (7 bucks?) is reasonable?

That's a good price. Mind holding on to them about a week til I know for sure I'm getting the heads and stuff? My zip is 75803

HOYS
12-14-2011, 12:01 AM
I've been holding on to them tightly for about 2 years in my garage....

chris_gt_74
12-14-2011, 12:51 PM
I've been holding on to them tightly for about 2 years in my garage....

LOL so I guess week more ain't ****.

AaronGTR
12-14-2011, 06:10 PM
96-02 are 10mm rockers. 03+ are 8mm. I have some 8mm rockers for you if you need them, used of course.


Not according to 60v6.com... http://60degreev6.com/content.php/29-60DegreeV6-Family-Tree


'03 - it says "revised cylinder heads" but doesn't state which engine or what changed.

'04 - it says "3100 and 3400 receive changes for common assembly with 3500 High Value V-6"

We know the 3500 only had 8mm bolts from the start, so I would assume the '04 changes to all 3x00's would include that, since it didn't specify in the '03 post. Now, if there is a thread or post in the forum of someone with an '03 engine who specifically states they have 8mm bolts, then that is another matter. In which case I would say they need to update the time line with more specific info so people know what years certain changes occurred without having to dig through the forum.

HOYS
12-14-2011, 06:37 PM
Not according to 60v6.com... http://60degreev6.com/content.php/29-60DegreeV6-Family-Tree


'03 - it says "revised cylinder heads" but doesn't state which engine or what changed.

'04 - it says "3100 and 3400 receive changes for common assembly with 3500 High Value V-6"

We know the 3500 only had 8mm bolts from the start, so I would assume the '04 changes to all 3x00's would include that, since it didn't specify in the '03 post. Now, if there is a thread or post in the forum of someone with an '03 engine who specifically states they have 8mm bolts, then that is another matter. In which case I would say they need to update the time line with more specific info so people know what years certain changes occurred without having to dig through the forum.


http://wot-tech.com/shop/articles/3400/3500-hybrid/cat_104.html

"8mm rocker arms are the only option for the 3500 heads, so for those with 96-02 3400, you will need the 8mm rockers to do the swap."

Also, I've torn apart an LNJ that had 10mm rockers. It is really a toss up IMHO.

The heads that he are looking at are for sure 10mm rockers and he for sure has 8mm rockers.