Hope this doesn't get me banned from the forum but if you can do all the swapping it sounds like you can do then I'd consider the 2.3 turbo ford 4 cylinder. They would make a heavy T-bird turbo coupe really scoot and turbocharging is the one thing that gives both more power and better economy. An engine supercharged in any way really gets a boost in torque. There are other turbo 4's around but most were for front wheel drive.
