There was a site that showed flow numbers and the only thing that out flowed the gt-40 from idel - 5,500 was the holly intake.

 

This might be of some help?


Dyno Number Trickflow R vs GT40

GT-40 vs. TFS R
A number of things are obvious from this graph. The first thing is that the TFS R made a great deal more power than the same motor equipped with a GT-40. Though 25 extra horsepower is nothing to sneeze at, the extra power was only available after 5500 rpm. Up to 5550 rpm, the modified GT-40 showed some pretty impressive gains from 3300 rpm all the way to 5550 rpm. Time and time again, the GT-40 continues to impress, though the TFS R intake clearly made more top-end power on this high-revving 347.





Here's another
Muscle Mustangs/Fast Fords super intake shootout
http://www.musclemustangfastfords.co...per/index.html

And I completely agree.... nothing beats the looks of a Tubular Gt-40!

 

PERSONALLY i'D RATHER HAVE THE POWER THAN LOOKS

 

Is there any way to put a better performing lower intake under the tubular gt40? or do you have to port lower gt40?

 

port it is the only way

 

I would seriously think twice about running a tubuar GT-40 on your 331. If this is an intake thats going on your current engine, you kinda have to ask yourself... "Do I really have the money to buy two intake manifolds??"

 

x2 My car already had the gt40 on it when I got it, if I was going to buy an intake it would be the holly sys.

 

It's weird though guys... from all the "flow charts" (I believe that's what they're called) the tubular gt40 intakes seem to out perform the other intakes from 1000 rpms - about 5600 rpms! With my setup I wouldn't need to go much past that rpm range! I dunno? if I got everything ported it would work awesome... correct?

 

Correct.

 

ok... I think I may try and find one then! exciting! does anyone know of any for sale? I checked ebay but all they had was the upper with no lower? so, If I bought the upper could I buy a new lower that would fit? do they sell the lowers new?