okay, so what are the mm's of ls6 throttle body's? i've seen 75mm and 78mm. what is the ls6 intakes opening? i currently have an 01 z06 but am getting a 05 cts-v with the 400hp ls6. i was looking at ported throttle bodies that are drive by wire. and im not sure what mm to look for, i'd sure hate to put a smaller one on if its even possible! any input would be great!

 

They are all 75mm, well the blade diameter is, stock there is a ridge that is 71.2mm so thats technically what they are before porting. 78mm tb's is all a myth from back when people thought since a stock tb is 75mm, a ported on must be 78mm. the opening on the intakes however is a true 78mm.