It's interesting that no one on this site has mentioned his other new parts such as the H.D. replacement 312 connecting rods, advertised in issue #88 of YBM. All focus seems to be on the Heads. In my humble opinion, say a person has already paid for performance reworked heads for a street machine. According to Mummert in past articles in YBM, flow tests have shown that even a somewhat reworked "B" 4 bbl intake, is definitely a restriction to cylinder head flow, on well reworked heads.. So, unless your are seriously into racing, the new Intake Manifold (despite my reservations about no choke heat availability!) would likely be a better investment, at an introductory price of $369, rather than spending $2100 on new heads.. Yes ?

Paul

Better breathing heads will improve the performance of an engine even if the intake is not upgraded at the same time.  There are already many out there with the Blue Thunder intakes on their Y’s so the heads will simply compliment their current combination but the new heads will still show an improvement with a stock intake in place.  You already see this in the circle track ranks where the stock intakes are required (many times with a two barrel carb in place) but head work or a better designed cylinder head is utilized to improve the engines performance.  The appropriate intake manifold will simply move the power bands around where the heads are more optimized.  This simply comes down to the sum of the parts making for a combination with different power attributes.  But most individuals opting for the new aluminum heads will very likely be using some form of aftermarket intake even if it's an older 3X2, 2X4, or one of the newer single four intakes.

Lorena, Texas (South of Waco)