Differences between a 440-4 and 440-6 parts wise.

[willhaven]

Aside from the carb setup, what is different between a 4 barrel and 6 barrel car? If I wanted to go from a 4 barrel to a 6 barrel car, what would it cost (with new non-original reproduction parts)?

How much performance do you really gain from a 6 pack setup?

[AMXguy]

The rods, cam and pistons ( compression ) are about it. I rebuilt my 440 with the heavy rods and everything to six pack specs incase I wanted to add it but on the dyno with an 800 CFM carb it's making six pack power. if I add the six pack it will be mostly for looks.

[Chryco Psycho]

the balancer & flywheel is also different with the Hp [6pack] engines
 you do not need all the HP parts to use a 6 pack , generally the advantage with the 6 pack is the carb is finally bug enough to feed a 400 wide open  & the cruising economy tends to be good using only the 2bbl most of the time
generally a single 4bbl in the 850 or bigger range with a good intake will match the 6 pack for HP