I am asking some intake manifold questions for a friend.

I notice that some guys are taking the LS2 TBSS intake and dropping them onto LM7 5.3 and LQ4/9 6.0 GEN 3 engines for power gains.

I was wondering if the LH6 5.3 intake manifold that was used on the 2004 Trailblazer EXT is the same as the intake manifold that was used on the 6.0 LS2 engine in the Trailblazer SS?

Would a 5.3 LM4 SSR intake be an upgrade over the standard truck 6.0/5.3/4.8 intake manifold?

What would be an average power gain seen by swapping a standard 6.0/5.3/4.8 intake manfiold out for an LS2 TBSS intake manifold on a 4.8 with small cam, headers and exhaust? Just a rough number is fine.

Thanks in advance

peace
Hog

 

The power gain comes largly from the larger throttle body. The stock intake on the 6.0 down uses a 3 bolt 78mm and the TBSS intake has a 4 bolt 90mm TB.
On a 6.0 you'll get anywhere from 10-15HP increase

 

Thanks for the response.

Anyone else?

peace
Hoig

 

The only motors that got the 90mm intake were gen 4 -tbss,ls2 ssr..The 5.3's in the ssr's and tb's still have the 3 bolt 78mm intake..

 

Actually they came with 87mm TB.. Only the Cars came with true 90mm TB

 

Can you just bore the stock intake on an LQ4 6.0 to accept a 90mm throttle body to gain most of that 10-15hp without swapping intakes?

 

Our v8 colorados have that intake and 90mm tb if I'm not mistaken. You should get on the v8 colorado forum since there are a few guys over there that have installed the FAST intake on their trucks. I personally think the factory intake will support more than enough power probally upwards of 500hp NA. Of course I've been wrong before.

 

Said the intake not the tb..

 

the V8s in the Colorado's use the gen4 Tbss intake that comes with a 4 bolt
87mm t/b but will also take the 90mm t/b from the Camaro

 

Hog, that's the easiest way to tell, from what I've seen there's no difference in any of the cathedral port 87mm intakes.... If you find one, go ahead and call it what you want lol.

Besides the obvious throttle opening difference, the runners are also shaped differently which helps top end breathing, and doesn't affect response or low/mid range power.