I have Cobra intake, GT40P heads, Ecam etc...and I just bought a 70mm TB. I also got a 75mm Granatelli (Pro-M) MAF to go with it, because a bigger TB without a bigger MAF is useless. I put the MAF in, and the gains were noticeable. I didn't put the TB in because they forgot to send the new bigger gaskets, which are on the way now. I spent 170 shipped on Ebay for one by MAC, MustangWarehouse sells them on there for that price.