LS3 Heads on a ls2

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Mar 24, 2021 | 07:11 PM

ConanElBarbaro

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From: Houston Tx

LS3 Heads on a ls2

looking to install ls3 heads on my ls2. I would like some info as how much i should mill the heads for compression 10:9 as per stock on ls2 or 11:1 and what gasket I could use. I currently have btr stage 3 cam and full bolt ons. I am going to send the ls3 heads for some port work. Any valuable info would be appreciate it. From what I heard this heads can be milled .030 and still clear pistons?

Thank you for any valuable info.

Mar 24, 2021 | 07:17 PM

Turbo6TA

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From: SW Florida

2021 C6 of the Year Finalist - Modified

You know you will need an LS3 intake manifold ... The LS2 manifold won't fit LS3 heads (different intake ports)

Mar 24, 2021 | 07:33 PM

ConanElBarbaro

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From: Houston Tx

Quote:

Originally Posted by Turbo6TA

You know you will need an LS3 intake manifold ... The LS2 manifold won't fit LS3 heads (different intake ports)

yes I knew that I have a Tony mamo ported Ls3 manifold

Mar 24, 2021 | 07:50 PM

Sleazy Rider

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Joined: Sep 2004

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From: Conroe Texas

Quote:

Originally Posted by Turbo6TA

You know you will need an LS3 intake manifold ... The LS2 manifold won't fit LS3 heads (different intake ports)

here is a ls3 manifold for you.

Mar 24, 2021 | 09:53 PM

veneno

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From: coconut creek, fl

I sent my ls3 heads to tsp for their port job and had them milled to 65cc
also went with thinner head gaskets felpro .041

Mar 24, 2021 | 10:03 PM

ConanElBarbaro

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From: Houston Tx

Quote:

Originally Posted by veneno

I sent my ls3 heads to tsp for their port job and had them milled to 65cc
also went with thinner head gaskets felpro .041

Thank you for the respond. Do you know what compression you are at now with 65cc?

Mar 24, 2021 | 10:04 PM

ConanElBarbaro

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From: Houston Tx

Quote:

Originally Posted by veneno

I sent my ls3 heads to tsp for their port job and had them milled to 65cc
also went with thinner head gaskets felpro .041

they told me to leave stock deck height and use a thinner gasket. They would just resurface the head so I’m just a little confused and trying to get the right info.

Mar 24, 2021 | 10:33 PM

veneno

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From: coconut creek, fl

i told them I wanted to raise the compression so they did 65cc
i used an online calculator wallaceracing.com and got 11.8 compression no issues with pump gas
you can find all the oem specs to enter in the calculator from google search I found the info on camaro5 forum

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Mar 24, 2021 | 10:37 PM

ConanElBarbaro

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From: Houston Tx

Quote:

Originally Posted by veneno

did you have to fly cut the pistons ?

Mar 24, 2021 | 10:38 PM

#10

veneno

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From: coconut creek, fl

1cc equals 1/10 reduction in compression so just thinner gasket aint gonna get you to 11:1
ls3 heads will drop your compression on an ls2 half a point

no left the pistons alone but I dont have a big cam
220/230 and 115lsa

Last edited by veneno; Mar 24, 2021 at 10:40 PM.

Mar 24, 2021 | 10:57 PM

#11

ConanElBarbaro

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From: Houston Tx

Quote:

Originally Posted by veneno

ok I have btr stage 3 231/244 LSA 12.5

Mar 25, 2021 | 08:55 PM

#12

Navy Blue 210

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From: Coast of San Mateo CA

Quote:

Originally Posted by ConanElBarbaro

ok I have btr stage 3 231/244 LSA 12.5

Way to Big for a 6.0 NA street car IMO, especially under 11.3:1 Comp.
Will drive like a total pos.
Is that a cathedral cam?
Going to need 4.10s & or 3600 Stall if auto.

Cam Motion LS3 Stage 3 for comparison 220/230 117

Last edited by Navy Blue 210; Mar 25, 2021 at 08:58 PM.

Mar 25, 2021 | 09:13 PM

#13

ConanElBarbaro

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From: Houston Tx

texas speed has a slight bigger cam they had mentioned. But i went with btr my choice. I like how it runs and just pulls but now would like to do head swap. after speaking with multiple shops and with the combo i have all 3 shops basically gave the same proper milling specs for my combo.

Thanks everyone for your feedback and input.

Mar 26, 2021 | 07:48 AM

#14

Last 1

Burning Brakes

Joined: Nov 2014

Posts: 971

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From: Whitesburg Kentucky

I’m like Blue Navy that car will drive like a pos without a gear if manual?my old setup was a ls 2 with CNC chevy ls3 heads milled .030 with .040 head gaskets and a 235/243 on a113+3 lsa . I had to fly cut the pistons to get clearance for the valves. And without the 4.10s it was a pos to drive.the car make 509rwhp /447 rwtq through a 3.42 gear.