LS6 Valley Cover - PCV Mod
I purchased the car recently with the only “mod” being a K&N air filter. I plan to do some moderate internal modifications over time (LT headers and EGR delete, stage 3 cam, oil pump, adjustable timing set, etc), then move on to suspension.
However, starting out, I found the air filter was saturated heavily with oil and the spark plugs had a considerable amount of oil on them. I replaced plugs/wires, cleaned and oiled the air filter, MAF, installed an SLP air lid, smooth bellow, port/polished the TB, and did the half shaft mod. I want to reduce the oil vapor and blowby by starting with the PCV system
My question is, with the LS6 intake and block, what do I need, to do the PCV conversion? I plan to install a catch can also. Do I only need the LS6 valley cover? And which hoses can be eliminated or need to be rerouted? I’ve seen the write up with photos on the conversion but it has instructions for the LS1 and C5 with LS6 mixed within it. If someone could break this down for just my specific setup, I’d appreciate it.
From the factory, there's a "U" shaped hose that goes from the valley cover to the side of the intake.
I ran a Mike Norris catch can on mine for years before I went turbo and went with the Mighty Mouse setup.
I mounted the catch can on the passenger head, one side of he the "dirty" side of the catch an went to the LS6 cover and the other side went to the intake.
I plugged the valve covers where the factory PCV lines attached to.
I purchased the car recently with the only “mod” being a K&N air filter. I plan to do some moderate internal modifications over time (LT headers and EGR delete, stage 3 cam, oil pump, adjustable timing set, etc), then move on to suspension.
However, starting out, I found the air filter was saturated heavily with oil and the spark plugs had a considerable amount of oil on them. I replaced plugs/wires, cleaned and oiled the air filter, MAF, installed an SLP air lid, smooth bellow, port/polished the TB, and did the half shaft mod. I want to reduce the oil vapor and blowby by starting with the PCV system
My question is, with the LS6 intake and block, what do I need, to do the PCV conversion? I plan to install a catch can also. Do I only need the LS6 valley cover? And which hoses can be eliminated or need to be rerouted? I’ve seen the write up with photos on the conversion but it has instructions for the LS1 and C5 with LS6 mixed within it. If someone could break this down for just my specific setup, I’d appreciate it.
My PCV valve is in-line between the nipple and the intake. After installing the LS6 valley cover, would this be the proper routing? I think the Elite would suit my needs as I’m not planning to make more than 400-450hp.
That place on the TB that the make-up air hose is hooked to, should go to a port in the front surface of the TB, ahead of the throttles butt behind the MAF. Lots of vehicles have that arrangement from the factory. Trucks bring it all the way through the TB to the plastic intake and the nipple going to the VC is back there. So if your TB has a passage like that, it'll work for yours too.
Not sure that "HP" has much to do with a catch can though.
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That place on the TB that the make-up air hose is hooked to, should go to a port in the front surface of the TB, ahead of the throttles butt behind the MAF. Lots of vehicles have that arrangement from the factory. Trucks bring it all the way through the TB to the plastic intake and the nipple going to the VC is back there. So if your TB has a passage like that, it'll work for yours too.
Not sure that "HP" has much to do with a catch can though.

No you’re right HP doesn’t matter, I was seeing different options from different threads that recommend MM over other catch cans, if HP is over 600. But pricing is the same and function is the same either way but Elite seems to make the PCV swap easier with the in-line PCV adaptor tube they include.
This is what my setup looks like currently. So after the LS6 valley cover, my valve cover/TB connection would remain the same. The PCV orifice would be connected at the catch cans inlet and the outlet would connect back to my intake manifold. The only thing I would need to do is plug off the inlets on the rear of both left and right valve covers. Correct?
Also would you recommend one catch can over the other? Or even a different catch can? I see MM all over the threads and I have an Elite on the (driver)
dirty side of my Silverado, which I’ve never had any issue with.
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Dorman also makes an updated drivers side valve cover that has improved baffling and a fixed orifice.
I didn't know the later cover's didn't have the fixed orifice in them. Thank you for that information.
Do all the LS6 blocks accept the later style valley covers? (I'm assuming it does, but you know how that goes)
On my 2000, LS1 obviously, I had to cut a section out of the block in the valley for it to fit.
I didn't know the later cover's didn't have the fixed orifice in them. Thank you for that information.
Do all the LS6 blocks accept the later style valley covers? (I'm assuming it does, but you know how that goes)
On my 2000, LS1 obviously, I had to cut a section out of the block in the valley for it to fit.
On the Vettes the '01-'04 LS1's were LS6 shortblocks with ARP rod bolts etc, but LS1 cam, and heads. The LS1s even got the LS6 intake.
MM is about 30% better separation efficiency than the several EE models tested
Newer LS-F kits include a new part we developed for the grommet on the driver rear making for a nicer install and get rid of the stock valve
FWIW, there was technically no "LS1" specific cam after the 2000 model year. From 1997-'00 the C5s had a specific LS1 cam, and from 1998-'00 the F-bodies had a different LS1 specific cam (F-bodies used an EGR system due to this, which C5s didn't need). Starting in 2001, all LS1 engines received the LQ4/9 truck cam, regardless of assignment to a C5 or F-body. At that point, the truck cam became the universal "LS1" cam.














