have you run that bored out throttle body yet? there is A LOT of measurement that goes into a TB, and they actually are not round, at least they aren't supposed to be... If you haven't run it yet, Id be surprised if it works right, and I dont mean that as an insult to your machining skills. Your stock 60mm TB has a cross sectional area of 2,826 sq. mm. rebored to 64mm gives you 3215, a 13.7% improvement. However, GM LS1 throttle bodies are $10 a pop in the you pull it yards around here and are 75mm (and still cable actuated, unlike the 90mm LS2 body, which is drive by wire), which gives you a whopping 4416 sq. mm, which is almost 2X the stocker...

 

I have ran the bored throttle body and it worked fine. It felt a lot like stock. It is a 67mm opening that tapers to a 64mm opening. It has pretty much the same shape as stock. I will soon be upgrading to a 68mm STR unit. 71mm tapered to 68mm. We will see how it works.

 

Real nice work, making aluminum welds look nice is a real skill.