carb butterflies catching on carb spacer?

[70 RAG TOP]

I am having a problem with the secondary butterflies catching on the carb spacer.  I have a stock dual plane manifold w/ 4 identical sized holes(1-11/16" diameter) I just bought a new Edelbrock thunder AVS carb, 650 CFM and I am using a 1/2" thick phenolic spacer.  The carb has 1-7/16"(primaries) and 1-3/4" (secondaries).  The holes in the spacer are 1-11/16".  Therefore there is a difference of 1/16".  When I manually open the secondary butterflies, they catch on the spacer and will not open all the way.  Did I get the wrong carb or do I have the wrong spacer?  I know that they make spacers with holes that are large at the top and taper down to the smaller hole in the intake.
Can anyone help me with this?

[Strawdawg]

I would want a spacer with holes at least as large as the blades in order not to reduce the potential flow of the carb you selected.

Open up the holes so they match the carb, or buy a different spacer

[Chryco Psycho]

I agree , clearance the spacer

[Aussie Challenger]

Open up the spacer but then the manifold will need opening up or you will have a ledge, you may have to blend the spacer secondary holes or the manifold holes so as there is a smooth flow and no restriction.   

[Strawdawg]

be surprised if the intake has a smaller opening than the carb blades

[Super Blue 72]

be surprised if the intake has a smaller opening than the carb blades

Weird but true if I read it right...

"I have a stock dual plane manifold w/ 4 identical sized holes(1-11/16" diameter)"

His secondary butterflies are 1-3/4".

[Strawdawg]

Weird but true if I read it right...

"I have a stock dual plane manifold w/ 4 identical sized holes(1-11/16" diameter)"

His secondary butterflies are 1-3/4".

Thanks, I never think about stock stuff....

[HP2]

Since the throttle blades are round and create an arc as they open, you may only need to clearance them very slightly on the two sides of each bore of the spacer along the axis of the throttle shaft to allow the throttle to smoothly open. If there is a 1/16 difference in overall size, you only need to smooth out 1/32 of space on each side, or remove it and simple rub it with some sand paper till everythiggn smooths out. It won't take much effort.

[UKcuda]

Since the throttle blades are round and create an arc as they open, you may only need to clearance them very slightly on the two sides of each bore of the spacer along the axis of the throttle shaft to allow the throttle to smoothly open. If there is a 1/16 difference in overall size, you only need to smooth out 1/32 of space on each side, or remove it and simple rub it with some sand paper till everythiggn smooths out. It won't take much effort.

    But ......

I had a similar situation - you can just hog out the edge of the spacer at the top end.  It doesn't take too much and you need to try to keep everything smooth.  But instead of just where they catch you might want to go all the way round the circle/s to avoid a step between the carb base and the spacer top.

[MEK-Dangerfield]

Wouldn't this be solved with going to an open spacer instead of one with 4 holes?   

[UKcuda]

Wouldn't this be solved with going to an open spacer instead of one with 4 holes?   

Depends on the spacer I guess, it could still maybe catch at the outside edges. 

[Aussie Challenger]

An open spacer would create a few turbulance problems between the bottom of the carb & manifold.

[Super Blue 72]

An open spacer would create a few turbulance problems between the bottom of the carb & manifold.

  You're going from a 4 holes/barrels, to an open space then the air/fuel in the open space (In the open spacer.) trying to find which one of 4 holes to go into the manifold.  You lose velocity in the open space then create turbulence trying to get iinto the intake manifold.