If you're not hung up on Ford then an LS7 in a BDR would be VERY SWEET. Ample room for growth with that 427 SBC which already produces great power.
505 horsepower @ 6200 rpm
475 lb.-ft. of torque @ 4800 rpm
7000-rpm redline
Read more:
LS7: The Largest, Most Powerful Small-Block Ever Built
Make a simple cam change and you have 680 hp and corresponding torque. BDR + LS7 = 1 high tech screamer.
Good luck, I'm sure whatever you decide will work out fine, test driving each is a wise decision.