would you have to port your intake for a 52mm throttle body?

 

No, the openings are already 52mm.

 

thanks

 

thanks

 

It's my understanding that the stock intake opening will support a 54mm TB.

 

I measured my stock LT1 intake, and the bores are EXACTLY 52.00mm. There is a tiny chamfer at the front that is obvioulsy a larger diameter, but the full thickness of the bore behind that is 52mm.

 

yup, im with fred. I had to open up the throttle when I installed it, so my 52mm TB lined up exactly with the bores, so I had a true 52mm opening at WOT. There is a little slack between all the bolt holes which adds up to a possible 2mm loss if not lined up perfectly.

 

so a 52mm is the biggest that you can go with a stock intake?

 

yup.

 

You can bolt whatever you want on it, but the flow through anything larger than 52mm is not going to be very smooth. AS&M claims their 54mm TB will work, but that extra mm on each side would seem to leave a "lip". Does the added turbulance offset the gains from the larger TB bores?