GM TBI on my 1970 360 duster

1. I think the fuel lines are too small to feed your existing combo, with a killer carb or not. I would look at the non braided push style hose from Aeroquip, Russells, or Earls. The non braided stuff is still rated plenty high for what you are doing, is relatively inexpensive, and you should only need a few fittings to make it all happen. Is there an aftermarket pump for TBI that will support the HP you are making, or do you need to go to a high pressure pump and regulate down. I am thinking #2 is the better way to go
2. The biggest TBI for OE came on the 454 chevy. I would think it to be the best option, to feed 400HP. I concern it might be too small?
3. No idea on ingnition
4. Have you looked at finding or using one of the Holley Projection units? They had 2 and 4 bbl units, and both of these used a standard square bore pattern, as opposed to GM's 3 bolt triangle pattern. I would think the 4bbl unit would be far better for airflow and fuel supply capabilities, and all would contribute to stock appearance underhood.

Used Holley Projection on ebay, 182.50 currently
http://cgi.ebay.com/ebaymotors/Holl...ptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories