Spread bore to square bore adapters

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DemonDave

DemonDave

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Anyone know if there's a carb adapter available to install a Thermoquad (850) carb onto a 70 340 squarebore intake manifold?

I checked Summit and they don't list the Thermoquad in their applications list.

Thanks
 
That's the one I was looking at but the applications list didn't include the T-Quad. I'll measure up the base plate on the carb to make 100% sure it's the one.

Thanks Adam
 
Edelbrock list one for a Thermoquad- part no. 2691. Most adapters are made for Q-Jets. There is a difference. The TQ adapter has more meat between the 2 rear bolt holes, the Q-Jet has less. If you use a Q-Jet adapter with a TQ, the passages on the bottom rear base of the TQ will be uncovered causing a major vacuum leak. Most gaskets are for the Q-Jet also so make sure you get a base gasket that covers all the passages. Edelbrock has one for Q-Jet and pictures of both. Make sure you get the 2691. If you watch swap meets you can find one once in a while also. That's how I found there was a difference.
 
That picture of that Summit spreadbore adapter is for a Q-Jet, will have a vacuum leak if you get that one.
 
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