I managed to get my hands on a very rare manifold for the Datsun. The manifold was created by racing tuner/business Far East Trading (F.E.T.) in the 1970’s in Japan. Upon my retrieval of the manifold I noticed there were signs of the 35+ year old manifold but that did not turn me off from the purchase as did a few of the other things I realized of this rare piece. First some background: It was said this manifold was actually made for the Japan only models of the 240z which contained the L20 engine and smaller carbs to match. The carbs used were the 38mm Mikuni/Solex as these were the ones that match up on moderately tuned engines (L20). The problem lays in the manifold has bore shapes for the 38mm carbs not the 40mm-45mm so common on the 240z U.S. engines (L24-0L28). Interesting enough the manifold actually tapers up (increase in diameter) the closer it gets to the head.
In the picture above I managed to measure 40mm on the carb side of the manifold and 44mm on the head side. Clearly fitting any 44mm carbs is out of the question on this manifold so this manifold is ideal for 38mm-40mm carburetors only and a mild cam cam. Probably around 280 duration and less than .5 inches of lift.
I ended up selling the manifold a few days ago for the sum of $260 (U.S. Dollars) as seen here in the pictures…minus the spider webs and one stud. One thing to note as these are rare in North America the F.E.T. manifold is easy to find in Japan and most Asian countries for that matter. There are better manifolds to be had for that kind of money and by “better” i mean better performance, not restrictive, better for idle, rarer, etc. In fact F.E.T. came out with another manifold with an air balance tube going across all the inlets. For my taste i would prefer the air balance tube and have my eye on one.