Zenith Complete: Work includes all of the above plus zinc plating/chromate of all applicable hardware, setting float level, verifying jets are true to size, set pumps to spec. A jet chart will be provided.   $3200

The original Zenith throttle housings were manufactured without any bushings at all. We install a machined brass bushing into each end of the housing, and then ream as needed to fit the new throttle shaft.

The original throttle plates are worn from rubbing on the bores.  To a lesser extent, the bores will wear too from repeated contact with the plates.  Some of bores have had surface rust or may have been "cleaned up" at some point.  These bores will no longer provide an adequate seal even when a new 32mm plate is installed. Excessive air will bypass the plate causing surging, a high idle, or lean popping. The housings above were bored to 32.38mm and then a new plate was machined to fit the bore.  A light source is placed behind the housing to illustrate the close tolerance between the throttle plate and the housing. No light is visible around the plate. You won't get a fit like this without an overbore.