"personally, IMHO you really need a WB O2 sensor to fine tune a street carb, otherwise you're doing a lot of stabs in the dark, especially when tuning the transitions between different circuits, and may be going in the wrong direction".

puuuuufst, no need to spend hundreds of dollars on something like that for a mild street car. get a vacuum gauge and a good timing light. That's all you need. If you choose to stay w/ the Eddy carb buy the tuning kit. The Eddy 750 will never be as good as the 850DP. Personally I'd use the 850 and get a drop base so you can use your air cleaner assembly. I'd also turn the fuel line backwards towards the fire wall, or get the split fuel line. It's not rocket science.