Has anyone (and I know this is probably a NO) done testing or flowbenching on the NNBS cathedral port intakes OR the 6.2 square port intake manifolds? (they look exactly the same except one is cathedral the other is square port)

The only obvious differences is that the NNBS intake has a smaller opening than the 6.2 intake does. I know because I can fit my hand in the 6.2 intake and feel around, yet on the NNBS intake I need a can of vasoline to get my hand in there and feel around.

 

Reason I ask is, I have both in my possession and I was thinking "how would this dyno with the NNBS intake setup"

But, I can't give a great dyno comparison as the only set of LS3 heads I have flow considerably more everywhere than my ported 243's, so theres no way I could just do an intake manifold test ONLY and change no other variables.

 

I didn't see any , which engine this heads + intake for ?

 

I'm not sure it matters frankly... They can't me mixed and matched so who cares haha

 

I'm not sure where you're going with this. They are not at all interchangeable, the bolt patterns are completely different, and the ports size & shape are also so different that neither one can overlap the other.

Your heads will determine which one you will use, period. And everybody (well I thought everybody) knows that factory rectangle ports flow better than factory cathedral ports.

 

You treed me.....

 

Are you comparing the plenum chambers?

Like the stock one pictured vs a ported?

The ported one being similar to L92 intake plenum you described?

Are you thinking about porting your nnbs intake?

 

NO. Let me try again.

I currently have ported 243 heads in my truck. I am about to bolt down the NNBS intake in place of the NBS intake and re-dyno.

IF theoretically I was to bolt down a NON-ported set of 823 square port heads (that would be similar in flow to what I have now) with the L92 truck intake manifold (looks alot like the NNBS intake) would the horsepower be close to the same, or is the L92 intake better than the NNBS intake?

I realize they aren't the same intake flange- which is why I hoped somebody had flowbench data for either of them (but nobody does so far?)

 

https://ls1tech.com/forums/6756797-post1.html

Some flow data on the L92 intake.