First off, I am by no means an expert...
Lately I was trying to pick a good dual plane intake for my stock 440 and did some searching in various forums and found many varying views and opinions. While many recomended the CH4B, others would claim it was nothing more that an aluminum version of a stock 4bbl intake. Others reasoned that the performer must be better than a CH4B because the CH4B is discontinued and old technology.
So I browsed, and noted, reviewed a few tests in Mopar Muscle and came to the conclusion that the CH4B is a slight step up from the performer in performance terms. I think the Pics here will show definate differences in all three.
First is a pic of a Stock 67-69 4bbl vs Edelbrock Performer. You can see similar runner sizes between the two, but the performers seems to have a more flow friendly layout.
Next up is the stock intake vs a CH4B. The CH4B has what appear to larger runners and sweeping runner design vs the stock piece. The CH4B also loses the stock choke mount.
finally let us look at the Performer vs CH4B. The CH4B appears to have larger runners and a slightly more swept and less angular runner layout but loses the stock choke mount and EGR mount. The Performer also will accept at spreadbore carb without modification but the CH4B does have enough meat to allow it to be "hogged out" to accept one as well if so desired.
