It was a $20 junkyard intake.....I did it over a year ago just to see what would happen, if it was useable I was gonna put in on my truck, as it was I did the LS1 intake swap with another intake because of the issues i ran into with the ported one

 

I have been working on my spare intake. I have taken the ports out to match my heads, about 1mm. Although, I have not tried to take any out of the runners, I don't think that the runner walls are thick enough. I have taken 1.5mm out of the TB intake, it seems small but every little bit helps.
It seems that you can do alittle to the intakes. Hopefully I will see some small gains. Although, it will be alittle while before my intake comes off, about a month.
I will still keep taking material out of the intake, to see how much I can take out. I know it probably won't be a SOTP feel but, alittle power is still more than I had.