Intake For 08 Denali

wht08 · December 31, 2009

I would like to replace the intake manifold/throttle body on my 08 denali, I was thinking about the LS3 intake or one off a LS7. Any suggestions as to which would match up with the rectangular ports on the L92 heads??

Nytemare · January 1, 2010

I am not 100% certain....but I think anything LS3 and newer has the rectangular ports. The LS3/LS7 TB will bolt to your truck intake though...the intake(center head) gives no real improvement...both intakes have a very similar design and flows almost exactly the same, the LSX intakes are lower than the trucks to fit under the hoods of cars, and the truck ones are made to fill up the engine bay in the trucks a little more. I know quite a few guys that have swapped and saw/felt absolutely no difference in either center head.

If you want one that will give you a little more go, and better looks...look for the LSX intake made by F.A.S.T, and couple it with one of they're TB's

66nova · January 1, 2010

Why do you want to change? What are you thinking you are going to accomplish?

007bonne · January 2, 2010

Sorry if I'm cutting in here, but are there any other stock intake manifolds (upper or lower) that would be an improvement for my 97 Yukon (5.7 Vortec) or 2003 Denali (6.0 HO LQ9 IIRC)?

Nytemare · January 2, 2010

your Yukon...I have seen guys swap over the TPI intake and MPFI system to a vortec 350..It requires more than a little modification though.

As for an LS motor...the intakes are port matched, and the same intake that's used on the 4.8L gets put on the 6.0L ...same with the car intakes...everything from the LS1 all the way up to the LS7 share the same intake. They're capable of flowing much more air than the car actually pulls in. If you want to do it for looks, thats a different story... LS1 car style intakes look much better IMO. But performance wise...from everything I have read, there is absolutely no difference...and according to some guys...not even a difference felt on the highly calibrated butt dyno.

wht08 · January 2, 2010

Why do you want to change? What are you thinking you are going to accomplish?

I will be adding an sts turbo in the summer and want to have the engine flowing to its maximum capabilities. as far as I can figure my denali engine is a restricted corvette engine, I know the cam has alot to do with that but I also assumed that the intake manifold was also restrictive. Better airflow was what I was hoping to accomplish

wht08 · January 2, 2010

I am not 100% certain....but I think anything LS3 and newer has the rectangular ports. The LS3/LS7 TB will bolt to your truck intake though...the intake(center head) gives no real improvement...both intakes have a very similar design and flows almost exactly the same, the LSX intakes are lower than the trucks to fit under the hoods of cars, and the truck ones are made to fill up the engine bay in the trucks a little more. I know quite a few guys that have swapped and saw/felt absolutely no difference in either center head.

If you want one that will give you a little more go, and better looks...look for the LSX intake made by F.A.S.T, and couple it with one of they're TB's

How is the performance gain on the throttle bodies? Worth the $$ or no??

Jennabear · January 2, 2010

your Yukon...I have seen guys swap over the TPI intake and MPFI system to a vortec 350..It requires more than a little modification though.

As for an LS motor...the intakes are port matched, and the same intake that's used on the 4.8L gets put on the 6.0L ...same with the car intakes...everything from the LS1 all the way up to the LS7 share the same intake. They're capable of flowing much more air than the car actually pulls in. If you want to do it for looks, thats a different story... LS1 car style intakes look much better IMO. But performance wise...from everything I have read, there is absolutely no difference...and according to some guys...not even a difference felt on the highly calibrated butt dyno.

X2 there is really no added benefit to changing it out.

flyin6 · January 3, 2010

I am not 100% certain....but I think anything LS3 and newer has the rectangular ports. The LS3/LS7 TB will bolt to your truck intake though...the intake(center head) gives no real improvement...both intakes have a very similar design and flows almost exactly the same, the LSX intakes are lower than the trucks to fit under the hoods of cars, and the truck ones are made to fill up the engine bay in the trucks a little more. I know quite a few guys that have swapped and saw/felt absolutely no difference in either center head.

If you want one that will give you a little more go, and better looks...look for the LSX intake made by F.A.S.T, and couple it with one of they're TB's

How is the performance gain on the throttle bodies? Worth the $$ or no??

For what you are wanting to do, you do not need to change anything. THe intake is fine, especially when you start to force air through it as with a turbo. If you were building a large motor, then perhaps a larger TB and the Fast intake would be advisable.

Do not spend the money on either an intake, TB or MAF, especially a MAF.

A note on the latter. Changing from a stock to an aftermarket MAF will make tuning very difficult. With adding someting like a turbo or a SC, you will definately be doing a lot of tuning. Keep your money and don't replace anything...

Nytemare · January 3, 2010

Why do you want to change? What are you thinking you are going to accomplish?

I will be adding an sts turbo in the summer and want to have the engine flowing to its maximum capabilities. as far as I can figure my denali engine is a restricted corvette engine, I know the cam has alot to do with that but I also assumed that the intake manifold was also restrictive. Better airflow was what I was hoping to accomplish

A friend of mine has an STS turbo on his truck with a 5.3 and has the truck intake...he's putting down 870ft-lbs That's RW Torque...and cannot keep transmissions in his truck....I dont think you have to worry about your intake dude.

Save your cash for a built 4L80E

Oh and BTW...the car intake is better for boost. It can take 2psi more before blowing apart.....ofcourse, the truck one takes 32psi before it comes apart...and the car one will take 34psi...you will lift the heads off the block with the cylinder pressure before you get to 32psi though.

007bonne · January 3, 2010

Any benefit to porting the stock lower intake.... or even just polishing? I do this a lot with 3800's with substantial gains, and considering my cost it would be minimal expense doing so if the gains are minimal.

Nytemare · January 3, 2010

If you can polish composite you can go right ahead.

And the LS intakes are port matched, this decreases turbulence which makes a better flow path. You can port them out...but without porting the heads to match...you would probably be pissing time and money away. and since the 6.0 in the trucks, and the 7.0 in the cars share intakes with they're smaller cousins....I would say on a 5.3 flow is nothing you have to worry about...and since the internals of the truck manifold are virtually the same as a car manifold...I would say the 6.0 doesn't have much to be concerned with for flow either.

I would say If anything...the weak link in the whole thing is the small TB...but its small like that for a reason too.

Spurshot · January 3, 2010

When I worked in a cylinder head shop, we dyno'd a set of heads (same set) with a traditional polish and then roughed them up. The roughed up heads produced something like 10 more hp on this 550 hp smallblock Chevy.

I believe GM Perf Parts catalog may have a section on intake manifold interchangeability with the various heads.

Nytemare · January 4, 2010

When I worked in a cylinder head shop, we dyno'd a set of heads (same set) with a traditional polish and then roughed them up. The roughed up heads produced something like 10 more hp on this 550 hp smallblock Chevy.

I believe GM Perf Parts catalog may have a section on intake manifold interchangeability with the various heads.

yeah there was a kid taht came in to my local machine shop with an edlebrock head that he just picked up for 100 bucks and did some porting and polishing on it...he wanted them to toss it on the flow bench to see how well he did...aparently the kid knew what he was doing....he bumped the flow up by 150CFM over the edlebrock numbers.

Unfortunately...the old guy at the shop than went over in the corner and grabbed an old Iron manifold and tossed that on the bench...it flowed almost 100CFM better than the one the kid had...almost 250CFM better than the Edlebrock...and it was stock...the old guy just said..."you need to know the right combination of stock parts to make Power...you dont need a 10 thousand dollar motor to make a tonne of power".