thermo quad question

[spudsterier]

i have a stock 360 iron intake manifold that i was going to put a new thermo quad carb on, but when the carb is on the intake, the butterflies wont open because they hit the edge of the intake.....
is there an adapter i can get to make it work?

 

[moper]

Did you try it with the factory type gasket? If it's a thermoquad intake, the carb should fit. If it's an AVS or AFB 340 intake, you will need an adaptor.

 

[needsaresto]

Is it the secondaries that are touching? Some Tq carbs have bigger secondary butterflies and a higher rare of flow. Could be you have one of these. Measure the secondary butterflies.

 

[demon sizzler]

Does your intake have 4 individual holes where the carb mounts? If so, it is likely an early 340('68-'70)intake. You will need a spread bore to square bore adapter. These adapters run $16-$20 and include fasteners/gaskets. Be aware that if your T.Q. is an 850 cfm, most of the adapters are designed for the 800 cfm T.Q.'s. The 800 cfm carbs have smaller 1.375" primary butterflies VS the 850 having 1.5" primary butterflies. The front and sides of the inner portion of the adapter is very restirctive just under the primaries of the carb and will likely need re-shaping. This restriction really hurts performance a lot, David.

 

[AdamR]

Heres a few pictures

Thermoquad intake on the left, AVS intake on the right

Of coarse the TQ wont even bolt up to the AVS intake

 

[spudsterier]

sorry guys.
i feel like a dumb ***......for some reason i put a spacer plate on the intake and the butterflies were hitting the side of the plate...
so i took the plate out and bolted the carb right to the intake and now there are no problems....
i think i just had a brain fart

 

[rumblefish360]

LOL, it happens to the best of us.

(The T-Q has 2 different primary sizes, 1 size secondary side.)

 

[moper]

All too often it happens to every human i know....lol