First things first...
There has been a lot of questions about what intake manifold to use.. LS1 or LS6. F.A.S.T will not work due to the rear bulge. Sorry....
Here is a test performed by TPiS. READ AND DECIDE FOR YOURSELF! http://www.tpis.com/pages/2_17_06
LS1 intake vs. LS6 intake flow numbers.
Stock LS6 head, LS1 intake....156...199...212...224...232...238...243. ..247
Stock LS6 head, LS6 intake....154...204...220...235...247...257...263. ..265
Stock cam with 1.8 rockers will provid about .510" non DOD and .520" DOD lobes lift. Valves will only reach peak lift numbers/flow once; and .050" lift twice. This is why the LS1 intake works after getting it's *** kicked above .450"
This is how I did my intake swap and the parts I used.
I will add links for the parts later
1/4 NPT to 3/8" hose fitting
1/4 NPT to 1/2" hose fitting
1 31/32" freeze plug
EV1-EV6 injector adapters
EGR plug (LS1 intake only)
LS1/LS6 fuel rail (non-returnless rail)
Intake gaskets, TB gasket
3M yellow weather stripping adhessive
You can get fittings here http://www.fastfittings.com/product/32006
Injector adapters http://www.bmotorsports.com/shop/pro...oducts_id/1765
Map extension harness http://www.bmotorsports.com/shop/pro...roducts_id/784
Start off by cleaning the intake with Gunk and hot water.
Remove the factory PCV fitting from the intake. You will need to gain as much opsu clearance as possible.
I used a dremel cutoff wheel. When the PCV nipple is ground down flush, plug the hole with some epoxy PUTTY.
Next remove the rear vacuum fitting.
Take a hacksaw, and saw the fitting off. Pry the rest of the fitting out with a flat blade screwdriver.
Here is what you'll end up with.
Next, plug the hole with a 1 31/32" freeze plug using 3M weatherstripping adhessive or epoxy. Then drill a 7/16" hole in the lower corner and mount the MAP sensor with a small screw. I used adhessive to seal the screw too.
Very tight fit!
If using a LS1 intake and it has EGR you'll need to plug the EGR hole
The plug pictured up above is found on E bay. You can also use Dorman 555-025 freeze plug for the EGR hole.
Now it is time to move onto the Vacuum fitting, and mod it for our power brake hose.
Drill the factory fitting out. Work your way up to a 7/16 drill bit.
Next tap the hole with a 1/4-18 pipe tap
And install a 1/4 thread 1/2 hose fitting using 3M adhesive as sealer. This will allow the factocy brake hose to remain in the stock location. No clamps required.
Move onto the bottom of the intake. The lower ribing will needs to be removed if using the DOD tray.
Here is what the bottom of the intake should look like after sanding or light grinding. Some intakes have curved bottoms and some are flat. Some DOD valley covers are thicker then others too! Remove a little at a time.
Brians TB adapter for use with headers
Drill and tap the star area with 7/16 drill, and tap with a 1/4-18 pipe tap and install a 1/4 pipe to 3/8 hose fitting for the dirty air PCV. The hose will go from fitting to the rear valve cover. Install with 3M adhessive.
I used LS6 injectors with LS6 fuel rail
Which required pigtail adapters EV1 to EV6. This allows us to use our stock harness. I have also include a pic of the MAP extension harness.
You can also use one piece adapters.
Now... In order to use the LS6 injectors/rail, you will need to remove your alt, and the alt bracket. The rear hump on the bracket has to be cut flush. It's pretty easy to figure out. Just use a vise and a hacksaw.
Here is a picture of the moddified bracket.
Tons of clearance now!
Everything assembled. MAKE SURE YOU BLOW THE INTAKE OUT WITH AIR TO REMOVE DEBRIS FROM DRILLING AND TAPING BEFORE INSTALL!!
Now it is time to move onto the DOD tray.
IF USING DOD LIFTERS, THEN YOU MUST USE THE DOD TRAY, even if the DOD is tuned out.
The OPSU will not clear the intake, so the OPSU port needs to be cut down to the DOD oil feed, and rewelded at an angle. 30* seems to work pretty good. Have a fab shop do the moddification. Try to retain the DOD filter if you can. If not, then be prepared for a clogged solenoid, or collapsed lifter if you decided to keep the DOD functional.
The DOD connector needs to be trimed down too, so pull the DOD connector out of the tray.
Next split into two
Trim the connector down as far as you can go. Then solder and heat shrink everything back together
IF YOU DO NOT PLAN ON USING DOD, THEN YOU CAN JUST PULL THE CONNECTOR FROM THE TRAY, AND WELD THE HOLE UP. JB WELD WILL WORK TOO! However.. The DOD Solenoids must remain intact. So bolt them back onto the tray after welding the OPSU at an angle
Tray isready to go. DOD still functionial!
Intake manifold bolts Guide
Install and ensure that all 10 intake manifold bolts are hand threaded as far as they'll go, tighten them down with a wrench and then torque in the order shown in the picture on the left. You need to torque these down in a 2-pass fashion..the first pass, tighten to 44 INCH-lbs, then, on the 2nd pass torque them to 89 INCH-lbs. Again, note those specs are in INCH lbs. If you don't have an inch pounds torque wrench, just tigthen the bolts hand tight...its only about 7 ftlbs of torque on that final pass and the intake seals with rubber gaskets so its doesn't need much pressure at all to seal.
Intake installed pic
New fuel line location. Bendings and twisting is not required.
Vacuum hose routing
Why the LS6 injectors and rail?
Well, for one... they are a bolt on item, and for two.. the LS6 injectors are pretty close to the LS4 injectors. LS6 are rated at 28.8lb and the LS4 injectors are a tad over 28lb. (58psi)
I'd rather cut up my alt bracket then the intake.
The engine will fire right up with the LS6 stuff, and will drive just fine till tuning. YOU WILL NEED TUNING.
SEE PAGE 4 FOR MORE PICS AND DETAILS!