Cory did that 2 years ago. It did work but nothing impressive. No point in having a TB bigger then your intake manifold. I know the JG is ported for a 65mm TB. Anything bigger is not worth it. I have a bone stock GSR TB on my car. I took off the 65 JG because of problems with TPS over a year ago and no difference. Granted this is a turbo application but 70mm is a waste. Try nitrous that will make power cheaply.