You have entered the Throttle body, intake manifold, uppper and lower plenum page.
This is the 3.4 intake stock it, it needs porting. It is not a good casting the ports can be made a lot bigger just by port matching them to the intake manifold gasket.

It looks like GM didn't put to much work (mental or phyical) into this casting.

This is a mod still in R&D it is a 75mm 2001 LS1 camaro throttle body with about 30,000 miles on it, I got it from ebay, I have cut apart the IAC housing of the old 2.8 tb and fitted it to the LS1 tb.
All it took was a saw and little file, I got lucky becasue the bolt holes all most lined up, I never even saw that coming.
I still need an adaptor to put it on the plentum and a TPS.

This is the old and new throttle body. MPIF 52mm vs. LS1 75mm
This was the upper plenum for my V6. Now I am transforming it into a MPFI/LS1 muntant.

Here is the V6 upper plenum that I cut up with my Miller 625 plasma torch to modify it to take the LS1 tb and flow a lot more air. Parts of the V6 plenum are about a 1/2'' thick.
There is a lot of meat for porting in this upper plenum.
Aluminium is harder for a plasma cutter to cut than steel because of how well it sinks heat away from the cutting point.
I did not think it would be any where near a 1/2'' thick so I did not have the torch turned up high enough and it got kind of messy.
I have yet to run into a job where the 625 wouldn't cut it.
Here is the LS1 tb flange, it is made of 3mm thick, 6061 aluminium alloy. Also this is what it looked like before I cut it.

Now the plenum has been cut up I ported the thick roof of the plenum so I can have more much needed air. I sand blasted it too.
It looks so nice now.

Here is a little info on intake runner design. This is a harmonic range chart I made on microsoft paint for the 2nd 3rd and 4th harmonic ranges.
It shows the benifits of shorter runners with longer harmonic ranges and long runners with shorter harmonic ranges lower but down in the rpm range where you could use them on a street engine.

Page 1 the completed projects page
Page 2 is cylinder heads and work
Page 3 is the fuel, nitrous and books
Page 4 The turbo page
Page 5 More turbo stuff
Page 7 Rotating assy.
Page 8 Exhaust and turbo headers
Page 9 Oiling system
Page 10 Fabrication form Aero space materals
Page 11 Chasse parts rengineering