Carb Spacer Question

dkamp said
I have a 340 HiRise intake that has only the smaller bolt holes. I would like to add a 1 inch spacer (Wood or Phenolic, not aluminum) for heat soak issues, but cannot locate a spacer that uses the smaller bolt pattern. The carb is a 1406 Edelbrock with both size patterns.
Any suggestions? Please help.
DavidK

View attachment 1716178143

That is not a HiRise intake, that is a stock intake.

Professor Fate said
Weeellll, It's not really "the small pattern", it's a spreadbore pattern manifold that you happen to have a square bore carb bolted onto.
Just get a Thermoquad spacer and you're good.
Fits Thermoquad Phenolic Carburetor Insulator Spacer Heat Soak Riser Mopar 1/2" | eBay

The Carter bolt pattern is actually smaller or more narrow from left to right looking from the front or rear of the carb, so he is correct. The early Carter WCFB, AFB & AVS carbs have this pattern.

dkamp said
I have been told that an Open plane (One big opening) gives higher Upper torque, and a 4 hole spacer gives better lower end torque.
If I go with this 4 hole version Mr. Gasket 3406 Mr. Gasket Carburetor Spacers | Summit Racing
(Mr Gasket 3406)
I wonder if the Carb butterfly's will have enough clearance?
Anyone know?
DavidK

That spacer fits a TQ?!?! Normally I see these for the QJ and NOT the TQ. The rear butterfly is 2-1/4 on the TQ, not so on other carbs.