Just thought I'd stir the pot a little.....
A turbo ford 2.3 is magnitudes easier than any V8 swap, costs the same or less than said swap, and will easily make stock SBC/351 power and torque (they came from the factory pretty equivalent to a 305). Mind you it won't have the same torque at anything less than 2000 RPM, but that's good if you plan on keeping the 7.5 out back. Once the turbo kicks in hang on tight. You can do fuel and airflow mods and crank up the boost pretty cheap too. 400-500 hp is not unreasonable and very doable with the stock bottom end.
Now I say it's easy cause I'm an EFI guy and scared of vacuum lines (not really), but if your a carb guy and scared of wires, this swap probably isn't for you.