Anybody know how big the stock throttle body is on an '06 Silverado with the 4.8?

 

78mm.

 

yep, 78mm

 

Thanks guys.

 

While the common factory ’99 thru ’07 Classic truck throttle body is called a 78mm, it is in fact closer to 75mm. I can’t say as to whether or not all the different variations (DBW & Cable) measure out exactly the same, as I don’t have an example of every configuration, but the opening of the intake manifold is basically 75mm as well, so it would make sense that they should also basically measure out the same. We know that all the intakes for the 4.8L thru 6.0L’s are basically identical outside emissions hook-up’s and whether or not they were for a DBW or cable operated truck, so I would venture to guess the throttle bodies are also sized accordingly. It wouldn’t have done much good to have a throttle body that was 3mm larger than the opening of the manifold.

Maybe someone else has some additional information on the subject.

 

Hello guys , I measured my 5.3 intake at 70mm and I've got a ls-1 I may install if and when I can find out who sells throttle plates . The ls-1 intake is 75mm which , btw , is a 15% increase in area . And an 80mm hole would be a 30% increase over the stock 70mm 5.3L intake opening . I have'nt measured my tb to see if they are different . So if anyone can help me with resources for throttle plates I would very much appreciate the knowledge . Thanx and good luck .

 

Ok.... so is it 78, 75, or 70mm?

 

Ive always been told 78mm.

 

I'm not sure what they say it is , all I know is the 5.3L intake measures 70mm and the LS-1 intake measures 75mm both at the opening .

 

I've always heard 78mm, but if Jarrod (1Bear) says that it's closer to 75mm, I'd believe that, he definitely knows his stuff