Carb spacers and Edelbrock 1405's

[Snag]

On a moderately built 305 with a Performer EPS intake manifold . This
thing runs like a scalded cat , did everything I wanted - except idle .
No matter what I did it would idle for a few seconds then just stumble
and die . Turns out that the spacer under the carb was the problem . I
had to use a spacer in order to have a vacuum port for the brake booster
since this carb doesn't have a port on the back . Turns out that because
the spacer is open without a center rib (and the manifold has one) it
causes problems with the idle circuits . The solution turned out to be
getting a spacer that has 4 holes instead of the open one . The new
spacer didn't have a vacuum port ... but it had enough meat to drill and
tap for one . And now the truck idles in gear without dying . I haven't
driven it yet to see if it runs differently on the road , but I don't
expect any significant change in performance .

[Paul in Houston TX]

  On a moderately built 305 with a Performer EPS intake manifold . This
thing runs like a scalded cat , did everything I wanted - except idle .
No matter what I did it would idle for a few seconds then just stumble
and die . Turns out that the spacer under the carb was the problem . I
had to use a spacer in order to have a vacuum port for the brake booster
since this carb doesn't have a port on the back . Turns out that because
the spacer is open without a center rib (and the manifold has one) it
causes problems with the idle circuits . The solution turned out to be
getting a spacer that has 4 holes instead of the open one . The new
spacer didn't have a vacuum port ... but it had enough meat to drill and
tap for one . And now the truck idles in gear without dying . I haven't
driven it yet to see if it runs differently on the road , but I don't
expect any significant change in performance .

Great bit of detective work!

[Snag]

Post by Paul in Houston TX

   On a moderately built 305 with a Performer EPS intake manifold .
This thing runs like a scalded cat , did everything I wanted - except
idle . No matter what I did it would idle for a few seconds then just
stumble and die . Turns out that the spacer under the carb was the
problem . I had to use a spacer in order to have a vacuum port for the
brake booster since this carb doesn't have a port on the back . Turns
out that because the spacer is open without a center rib (and the
manifold has one) it causes problems with the idle circuits . The
solution turned out to be getting a spacer that has 4 holes instead of
the open one . The new spacer didn't have a vacuum port ... but it had
enough meat to drill and tap for one . And now the truck idles in gear
without dying . I haven't driven it yet to see if it runs differently
on the road , but I don't expect any significant change in performance .

Great bit of detective work!

Not my detective work though . The credit goes to a friend who has
more experience with performance mods . I've maintained all our vehicles
over the years , but this is pretty much my first foray into performance
mods . And likely my last considering I'm no spring chicken anymore .

[Paul in Houston TX]

Post by Paul in Houston TX

   On a moderately built 305 with a Performer EPS intake manifold .
This thing runs like a scalded cat , did everything I wanted - except
idle . No matter what I did it would idle for a few seconds then just
stumble and die . Turns out that the spacer under the carb was the
problem . I had to use a spacer in order to have a vacuum port for
the brake booster since this carb doesn't have a port on the back .
Turns out that because the spacer is open without a center rib (and
the manifold has one) it causes problems with the idle circuits . The
solution turned out to be getting a spacer that has 4 holes instead
of the open one . The new spacer didn't have a vacuum port ... but it
had enough meat to drill and tap for one . And now the truck idles in
gear without dying . I haven't driven it yet to see if it runs
differently on the road , but I don't expect any significant change
in performance .

Great bit of detective work!

  Not my detective work though . The credit goes to a friend who has
more experience with performance mods . I've maintained all our vehicles
over the years , but this is pretty much my first foray into performance
mods . And likely my last considering I'm no spring chicken anymore .

I know the feeling.