colorado808

iTrader: (3)

I'm wondering if anyone else has their rear steam block offs already blocked. As you see in the pic there's only a hole for the screw and the dowel cannot go in to seal...do I still need to block this off? I didn't want to drill it if it doesn't need to be and I didn't want to remove heads either. Any help appreciated.

blake b

iTrader: (11)

You need these. I don't know the part number for the actual apparatus but the GM part number for the seals are 12551933 (air bleed gasket plates). They are the little plate on the end. You can barely see the rubber o-ring that goes around the dowel that does the sealing in the plate.

LS1MCSS

iTrader: (18)

I think GM blocks off the rear steam holes on the newer L92 heads. If yours have already been blocked then you don't need to do anything else there.

colorado808

iTrader: (3)

Those are the ones that I currently have but they don't fit because there is no provision for the steam hole, only the screw in.

S10xGN

iTrader: (11)

As LS1MCSS said, yours are already factory plugged so you need to do nothing else.

Zbinkley

So you can block off the rear steam ports? I was just going to mod my steam tubes with a hose looping over the intake. but that would be sweet if i didnt need to do that.

S10xGN

iTrader: (11)

GM started blocking the rears when they went to the LS-6 manifold.

LS1MCSS

iTrader: (18)

The newer L92's heads are plugged in the head.

oakley6575

iTrader: (3)

That is sweet. If I order LS3 heads from the dealership right now, part number: 12629063, do you guys think they will come blocked off in the rear?

MattSapp95_T/A

iTrader: (35)

Mine didn't....

I had to use the block offs that were on my 317 heads...

oakley6575

iTrader: (3)

Dang. But I do think thats cool that they are blocking them from the factory

DietCoke

iTrader: (18)

My LS3 heads don't have steam pipe connections.

MattSapp95_T/A

iTrader: (35)

Thats weird...do you have a pic?

DietCoke

iTrader: (18)

Ill doublecheck my clutch install pics when I get home, that's when I noticed it. Might just be a factory installed ls3 thing.

93Z2871805

iTrader: (5)

Setup for block-off plugs here, my LS3 (with blue springs) heads were bought about a month or two ago (but who knows how long they were on the shelves).

litle88

iTrader: (20)

I just bought a set of LPE cnc'd heads and they came with the steam holes tapped and ready for installation on both sides so no block offs hear.

ultradriver10000

iTrader: (13)

Wouldn't you rather allow the heads to vent?

oakley6575

iTrader: (3)

Just received my 0821 LS3 heads and the back ports aren't blocked.

1A Dan

iTrader: (9)

mine were used when i got them and were blocked off. i wanted to run the steam tubes in the front and back, so i used an old truck steam tube block as a guide and drilled em out.

litle88

iTrader: (20)

Show me your set up please. Ive been debating this all spring and I decided to pull the trigger.

Thanks