What size is the 1998 factory LS1 throttle body, measured in millimeters? I did try looking for it but couldn't find the information. It appears, just by eyeballing it, to be in the 65-68mm range but I didn't take too hard of a look.

What size can a factory LS1 throttle body be ported too safely and reliably?

The reason I ask is because I am looking for a ported factory throttle body and I have found everything from 75mm - 93mm . Can a factory throttle body be ported to 93mm? I didn't think it was possible. Most aftermarket intakes advertise a 78-85mm opening. My thinking is that even if it is 93mm, it would be wasted on my factory LS1 intake.

What size for a stock engine, with just a lid and the free ram air, should I shoot for?

Thanks in advance.

 

my stock throttle body was ported to around 78-80mm, i don't see how they could port a stock throttle body to 93mm, could the 93mm ported throttle body might be a fast90mmtb or a nw90mm tb?

 

Just a porter stocker would do you fine

 

Even if you port your stock throttle body the blade size is not changed. So the opening for the blade would be the same as stock. the benefit comes from the opening of the throttle body being properly contoured to promote better airflow characteristics.
This may also explain the difference in sizes that you have seed, depending on where they measuered it. And I thought they were 75mm stock, But I could be wrong

http://www.lmperformance.com/6074/1.html (example)

 

i believe the butterfly is 78mm, so its called a 78mm. the passage gets smaller then that like say 76mm. when someone ports it they open the full passage to 78mm. i read that somewhere.

 

https://ls1tech.com/forums/generatio...b-porting.html

If you dont believe, here you go.