Ls2 - ls7 rocker upgrade

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Oct 18, 2009 | 08:15 PM

martysauto

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Drifting

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From: cinnaminson n.j.

St. Jude Donor '14

Ls2 - ls7 rocker upgrade

Has anyone swapped out their 1.7 ls2 rocker arms for 16 ls7 exhaust rockers to go from 1.7 to 1.8 ratio? It appears to be an inexpensive way to gain some lift.

Oct 18, 2009 | 08:25 PM

jpee

Race Director

Joined: Oct 1999

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From: Somers NY

I was thinking the same thing...also would it require a valve spring or push-rod change ?

Oct 18, 2009 | 10:21 PM

SweetS10v8

Instructor

Joined: Dec 2007

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Its been discussed before and I dont remember the reason, but you cant jsut swap it like you want to.

Comp Cams makes 1.8 Ultra Gold drop ons
SLP also makes some 1.85 drop ons

Oct 18, 2009 | 10:33 PM

martysauto

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Drifting

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From: cinnaminson n.j.

St. Jude Donor '14

How about yella terra ultra lites? I like the idea of the shaft mount since the 8mm bolts has pulled the threads out on stock gm v6 engines with a similar set up. I have just seen pictures of stock ls7 rockers spitting out the needle bearings.
Will the stock valve springs handle the added lift of 1.8's (about .030") with the stock ls2 cam?

Oct 19, 2009 | 12:08 PM

JoesC5

Team Owner

Joined: Sep 1999

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From: Springfield MO

Quote:

Originally Posted by martysauto

Has anyone swapped out their 1.7 ls2 rocker arms for 16 ls7 exhaust rockers to go from 1.7 to 1.8 ratio? It appears to be an inexpensive way to gain some lift.

If I remember correctly, the LS7 heads have larger ports and they have an offset intake rocker arm that is different from the LS2. I think the intake rocker arm studs are in a different location relative to the valve stem.

Oct 19, 2009 | 12:17 PM

tjwong

Le Mans Master

Joined: Jan 2003

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From: Portland Oregon

You can't use LS7 rocker arms on anything but a LS7 or another head that would use the identical offsets.

Oct 19, 2009 | 08:10 PM

martysauto

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Drifting

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From: cinnaminson n.j.

St. Jude Donor '14

That's why i was going to use 16 EXHAUST rockers. After seeing what happens to the ls7 rockers, their out anyway. Yella Terra is what I'm leaning towards.

Oct 19, 2009 | 09:47 PM

Joe_G

Tech Contributor

Joined: Jul 2002

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From: St. Louis, MO

St. Jude Donor '08

LS7 1.7's don't fit, and I've never seen anyone here be happy with a rocker arm change. It's a lot of labor and money (new springs needed) for virtually no gain.

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Oct 19, 2009 | 10:46 PM

martysauto

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Drifting

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From: cinnaminson n.j.

St. Jude Donor '14

Thanks for your replies.
Any thoughts on a ported stock intakefor my ls2?
I'm hearing their good for 10-12 hp.
How about ported throttle bodies? They seem to have mixed feedback.

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