The 460 is at least 6 inches longer ... than a SBC
The 460 is at least 4 inches wider ... than a SBC
The 460 weighs at least 200 pounds more than my 350 SBC

If you are going to build a Highboy car ( no original style front fenders ) then you could move the crossmember forward a little and gain a little room. The rest would HAVE to be in the firewall unless you extend the chassis. If you are building a coupe or a roadster ... 3 or 4 inches out of the floor board makes for a very cramped interior unless you are smaller and shorter than the average American man. ( I believe the average is 5 foot 10 inches )



There is NOT a lot of foot room ... to lose in a coupe/roadster