Simple question I hope... Im putting together my first Gen III engine, mild little 6.0L should hit about 500 hp. One of my questions is about using the 6.0L intake manifold. This will be in a heavy car (4500#) and hood clearance should not be an issue. Which is better and by how much for an engine that needs some good bottom end torque, the truck manifold or a LS6 intake? I have heard that the truck intake is pretty good. Is this true? Thanks!

 

I don't know this for a fact, but I would imagine that the truck manifold would be geared more towards low-end torque than high-RPM power. Maybe someone else can chime in on this..

 

Let me also add that my shift point should be somewhere between 6500-6800 rpm I think.

 

i they did this comparison on the truck side..they said that the truck intake flowed right with the ls6 to about 5500 but then fell on its face..do a seach on the truckperformance website.

 

He's right, the LS6 outperforms the truck manifold (accross the board, I believe) but very much so above the 5500 mark, like he said. Go with the LS6, it's your best bet

 

the long runners of the 6.0 intake stifle its rpm capabilities. that being said, whats the rest of the combo?

 

I have tried to push that intake as far as it will go. It is no good above 5,000 RPM from what I have seen.

All testing with this was done on an '04 Silverado SS. After trying everything I could think of everything I did pointed to the intake absolutely killing me.

Silverado SS:
Heads(Patriot SIII/mild mods by me)/Cam(231/237 custom cam)
200 wet shot
Headers
Tuning
Volant CAI
Converter
22" Rims and Nitto 555s
Pump gas
Dropped 2.5/4 and air bags

The truck eventually went mid/bottom 11's. I feel we could have cracked into the 10's with a good intake and a trans that wasn't on it's way out.

If you're not running a mild engine that you want modest performance from ditch this intake.

 

I think Chevy Hi Performance did a side by side flow test back in 04 on these but I cant find the article. The flow numbers were close, I just dont remember where it fell off at. I was hoping the 6.0L intake would be close to an LS6 but its not looking that way so far. I can get one almost new w/ everything on it for under $100 vs what the LS6 intakes fun. Just tryin to keep it a cheap project. As for the rest of the engine... nothing is set in stone, Im still accumulating parts.

 

consider also an ls2 intake

 

I saw the same test. I have the mag somewhere around here. I don't care how close they look on the bench. When you start leaning on the motor it's a detriment.

If you are building a mild engine it will be fine.