I run a homemade 3 x 2 setup on my Logghe chassied Nostalgia racer that uses three 350 2V main bodies taper-bored out to accept 500 2V base plates. Good throttle response and on a U-flow head they work OK, but my X-flow head needs (3) 540s. Similar principal as what can be done on your 4V.

FORD 300 inline six - THE BEST KEPT SECRET IN DRAG RACING!