Not sure if these are misprints, but the book states that the 4.8-5.3 have 75mm throttle bodies, and the 6.0's have 80mm throttle bodies. I thought they were all the same. For kicks, I checked AC Delco's website, and they list different part numbers for 5.3 and 6.0 '99 trucks. Wouldn't that make the opening for the intake a different size also?

The book also lists the LQ4 6.0 as 364 cubic inches, and the LQ9 as 377 cid

 

IMO some of the info entailed in that books is a tad skewed.

 

i will have to check on this cause i have a 6.0 throttle body.never though of that.

 

Hmmmm....How could that be?? I tought the Lq9 and the Lq4 have the same displacement. The Lq9 was the higher compression motor.

Check out this link is very intresting about the GENIII motors:http://www.automotiverebuilder.com/ar/eb040538.htm

 

That was an interesting read, I learned a lot from that.

 

you referring to this: http://www.automotiverebuilder.com/ar/eb040538.htm
yea, there's alot of good info there. I'm still unsure if the 4.8/5.3 throttle bodies are a different size than the 6.0's...especially since AC Delco shows 2 different part numbers for them. Might have learned something new.

Oh yea, another part of the book mentioned 85mm throttle bodies that are offered on Corvettes and some trucks....not sure about the vette, but I thought that all the trucks had 78mm tb's...now they throw another tb into the mix...

I think the LQ9=377 has to be misinformation though...where do the extra 13 cubes come from? Something's a little off...

 

Sorry to bring up this old thread, but anybody dig any deeper into the throttle body sizes on different engines? Just curious, because I had been keeping an eye on this thread, and it kinda died out.

 

My TB from my 00 5.3 and my 02 6.0 were the same size. They were identical. Maybe teh LQ9 is different?? I thought the 6.0's were both 364 ci, but I did see somewhere that the LQ9 was 366?? WTF

 

That would mean the LQ9 is a 6.2L I'm sure Chevy would advertise that if it was true.

 

The LQ4 and LQ9 are the same displacement, as far as the throttle bodies there are the same also to the best of my knowledge. I can tell you that my denali with the 6.0 has the same throttle body as my 03Sierra had with the 5.3, I believe when that book was printed Chevy was still up in the air as too exactly what the LQ9 was going to be, in the preproduction stages it was actually a 6.2 but the final production got the 6.0 with a little higher compression.