I ran across an oddball intake manifold today that was on a 2005 Trailblazer 5.3. It's the common truck intake but had a 4 bolt TB like the NNBS/TBSS manifold. Was this a one year only manifold? I found a few threads on the net about it, but details were scant about this manifold. Is there anything unique or worthy about it that it's worth picking up? I'm looking for an intake manifold for an lq9 going in my truck and I've never seen this combo before.

I should have looked closer when I was there, but does anyone know if this 4 bolt 87mm? TB is the 6 wire or possibly an earlier 8 wire like Gen 3 trucks used? I might have to pay another visit to find out if no one knows.

I found a thread somewhere that mentioned this intake being used on the SSR thing too, but the one I saw was on an "M" engine 2005 Trailblazer 5.3.

 

The GEN 4 manifolds are all 4 bolts, so that 5.3 is a GEN 4 because they also had AFM/DoD.

It's a LH6 version, aluminum block with AFM. The 2005-2006 trucks used the E40 GEN 4 computer and the 2007+ used the E67 GEN 4 computer.

Off hand I am not sure on the throttle body harness connector.

 

It's a 6 pin connector 87mm TB.

As mentioned its basically a truck intake with a 87mm 4 bolt setup.

 

Thank you both for the replies and information on this one year manifold.

In ranking factory intake manifolds, would this particular intake manifold, or the later NNBS/TBSS intake manifold be a better choice for a daily driven 1/2t truck with a 6.0?

I have 3 intake options here
-stock 2004 truck intake
-this 2005 hybrid truck intake w/ larger TB
-NNBS/TBSS; 06+ LH6 intake manifold that I have on the shelf
Is the order I have them in accurate, from least to better?

 

 

I guess technically it would be correct.

 

AFAI K , there are about 15 - 20 different part numbers for that gen IV intake. The TBSS is the only truck intake that has a 90mm intake, all the rest are 87mm.

again, AFAI K , unless you just need an intake, this one is no different than any other gen IV intake. Unless you have: a cam, at least mild head work, tune, exhaust, then any intake is going to work. If you have that done or more, than you want the TBSS intake or something better.

 

I was thinking about this manifold again and wanted to add to this post and pose a follow up question about it. In some post I previously read here on PT.net, it mentioned that most of the hp gains from a TBSS/NNBS intake manifold swap comes directly from the larger 87mm throttle body vs. the gen 3 truck manifold and it's 78mm throttle body. I can't seem to locate that older post or thread now that I've been searching for it. Is that verifiable truth about the throttle body size being most of the improvement? I seem to remember something in that previously read thread about the inside of this 2005 LH6 manifold necking down to the smaller ~78mm, but memory is foggy on that detail.

The path I'm heading down is, if the larger TB premise is true, then would using this one year 2005 LH6 only intake solve a few problems for those of us wanting to do this swap on a gen 3 truck engine, lq4, lq9, lm7, l59. By using this manifold, you could stick with your factory fuel rails with their return line from the original 3 bolt TB intake manifold, requiring no need to re-engineer the fuel rail and lines to accommodate the TBSS/NNBS manifold non-return line fuel rails. You'd also achieve the larger 87mm 4 bolt throttle body at the same time with this manifold. Anyone explored this option?

Is there a significant difference, flow wise, in the TBSS/NNBS manifold itself vs. the widely used gen 3 truck manifold, outside of the throttle body?

I have seen 2 of these manifolds over the last 4 months at the local PYP, which is what got my gears turning on this option instead of doing the more conventional TBSS/NNBS intake manifold swap. Thanks in advance for any and all insight fellas.

 

Well yes and no about the throttle body. Yes because you need the larger throttle body to take advantage of the intake's manifold larger mouth. No because you need the intake manifold to take advantage of a larger throttle body.


Basically just FAST LSXRT and call it quits.

 

I would do any gen4 with a 90mm on it before dropping the money on an LSXRT

I put a P1 kit together for what FAST wants for that thing new, and guess which ones makes more power? lmao