LS3 Need help with connections

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Oct 22, 2021 | 08:04 PM

jaredlgoldman

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LS3 Need help with connections

I rebuilt an LS engine from a Chevy Silverado. I have dropped it into my 1957 Chevy 3100 project. I am struggling to figure out where all the misc connections go. Below is a picture reference and questions

Connection #1

Yellow tape in back - open port - What is this for?

Connection #2

Hose coming off intake manifold

Connection #3

Hose coming off front of intake manifold ?

Connection #4

Yellow tape covering intake tube on top of valve cover - what connects here ?

Connection #5

Intake open tube on top of blower - what is this for ?

Connection #5

Cap on side of intake manifold - behind the blower - what is this for ?

Connection #6

Steam valve front of engine - where does this connect ?

Connection #7

connection on spacer behind water pump - front of engine - where does this connect ? to the steam valve ?

Any help would be appreciated
thanks

Last edited by Che70velle; Oct 23, 2021 at 10:31 PM.

Oct 24, 2021 | 02:38 PM

wannafbody

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#2 I think is a brake booster hose
#3 is the evap return line which connects on the drivers side front of the intake, at least for a LS1/LS6 intake.
The cap looks to be for EGR which you probably don't have.

Oct 24, 2021 | 06:32 PM

jaredlgoldman

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Thanks for your help.
#2 brake booster is what I thought
#3, I have to check on the intake drivers side. I don't think I have that

Any other thoughts on the other connections ?

Oct 24, 2021 | 06:59 PM

JimMueller

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From: Casselberry FL

1) Rear driver valve cover PCV outlet? More recent designs have that port capped, but some PCV designs still incorporate it.
2) Brake booster
3) I have a hose like that which connects between a nipple on the front driver side of the LS3 intake manifold and a EVAP solenoid which lays in the crevice between the manifold and valve cover.
4) Old style passenger valve cover where the PCV outlet was horizontal instead of vertical. Often directly connects to #5-2 below unless you have a catch can.
5-1) This is a truck intake, unsure what fitting that may be. The L76/LS3 manifolds have a vacuum nipple on the rear of the manifold; perhaps the truck intake has it on top?
5-2) I think this is supposed to connect to #4 above?
6) Some older LS cars had a coolant pipe going from the front driver steam port, to the OEM throttle body, which in turn went to the radiator fill neck. Perhaps this is the truck orientation? Most change that layout to bypass the TB and go direct to the radiator.
7) I don't recognize this port