The 700R4can be had without a lock up converter as well, for a non-computer of any kind installation.

EFI (electronic fuel injection) comes in several forms - multi-port injection, throttle body injection, etc.

Cost? if you want to open teh box and go, or pretty close to that anyway, carbs are cheaper. If youare willing to work at it, EFI can be cheaper (seacrh web for MEGASQUIRT).

If you are computer phobic and have no computer capable frineds, perhaps carbs are the way to go. (many aftermarket systems require a PC computer hookup for tuning and
troubleshooting)

If ultimate balls to the wall HP is the goal, carbs may still have an edge, albeit a small one.

I am an EFI fan, and plan to go that way on all future projects...The Camaro is goinf big-buck Holley or Edelbrock (this winter is for reasearch on what i can get) and my old lincoln is going Megasquirt.

EFI beneftis? generally speaking, better driveability, better mileage, better bottom end without hurting top end, easier starting, less emmissions.