I agree, I would not even consider swapping my 351W for any big block. There is no need to, you can get the same power out of a lighter engine.
------------------
67 Fastback - Arctic White Pearl paint
351W ,Trick Flow Aluminum Heads, Edelbrock TorkerII, Comp. Cam, Performance Automatic C-4 Trans, 3.55 gears, Front Disc Brakes, 1-1/8" Fr. 3/4" rear sway bars.
My 351W Fastback