That is an awesome 64 with what looks like a 66 front clip. I have single turbo on mine and there are a few others with singles also. Downpipe routing is the toughest if you are working around tortion bars. I've considered twins and I think a couple of small ones would work mounted in the fenders behind the headlights with 3" downpipes routed over the tops of the tires and down and out or towards the inside and piped to dual exhaust. I semi mocked up my GT45 inside the fender which is a pretty big turbo and it cleared.
