Later Thermoquad Carb On Earlier Intake Manifold; Help!

[philcoradio]

Hey all,

I recently picked up a ‘69 casting 2806178 intake for my ‘78 440 and I’m in the process of putting my C4-TQ thermoquad carb on it. I stumbled into the problem that the carb bolt holes do not line up at all. Is there an aftermarket spacer I can use to fit this carb on the earlier intake? Or do I need a whole new carb? I’d like to keep the carb since I already bought the rebuild kit, but if I have to get another one, which one should I get? Not trying to spend too much on one since I plan on making some performance upgrades to the engine later this year (intake, cam, heads, pistons, etc).
Carb: C4-TQ 9247S
Original intake: 3830733
‘69 intake: 2806178

I used the original base gasket to show how the carb would fit on the original intake and the ‘69 intake.

Any help is appreciated. Thank you!

Chris

 

[WileERobby]

There are square bore spacings and spread bore spacings for carb mountings.

 

[toolmanmike]

Hey all,

I recently picked up a ‘69 casting 2806178 intake for my ‘78 440 and I’m in the process of putting my C4-TQ thermoquad carb on it. I stumbled into the problem that the carb bolt holes do not line up at all. Is there an aftermarket spacer I can use to fit this carb on the earlier intake? Or do I need a whole new carb? I’d like to keep the carb since I already bought the rebuild kit, but if I have to get another one, which one should I get? Not trying to spend too much on one since I plan on making some performance upgrades to the engine later this year (intake, cam, heads, pistons, etc).
Carb: C4-TQ 9247S
Original intake: 3830733
‘69 intake: 2806178

I used the original base gasket to show how the carb would fit on the original intake and the ‘69 intake.

Any help is appreciated. Thank you!
Chris

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Your Thermoquad carb will not work on that intake without a adapter. You might need one for a GM Quadrajet carb as long as the bolt pattern is the same.

 

[rumblefish360]

The 4 hole (square bore) intake isn’t for TQ carbs.

There are adapter plates available though I’d go to the correct intake manifold. It’ll be much better off that way.

 

[pnora]

Why not use the later spread bore intake? You can close off any emission ports.

 

[RJRENTON]

The 4 hole (square bore) intake isn’t for TQ carbs.

There are adapter plates available though I’d go to the correct intake manifold. It’ll be much better off that way.

ABSOLUTELY correct.....change the manifold to match the carb you want to use OR use your existing manifold and place a for sale ad for the T-Q rebuild kit and use the proceeds of the sale to buy the rebuild kit for your original Carter AVS carb. IMO, the origional AVS (or the Edelbrock or "Eddy" equilivant )will be easier to tune for your anticipated/fourth coming revisions....... just a thought.....
BOB RENTON

 

[70bigblockdodge]

I would get a later intake. They are easy to find and are honestly a better intake with more interior volume. Downfall being the EGR porting which can be blocked easily.

 

[Darter6]

Looks like you have the correct spread bore intake.That's what the photo shows. Use it.
You will have no gain using the 69 manifold.None.The spread bore will flow as good if not better. I am a big fan of Thermoquads. Great carbs.
OR if that's not your spread bore manifold,get the correct carb for the 69 manifold.

 

[70bigblockdodge]

Missed that, yes use speadbore intake

 

[peabodyracin]

Years back I tried a number of times to use adapter plates because of lack of funds. At least 90% of the time it didn't work out well. You'll likely have trouble getting a good seal around the secondaries and hood clearance might be a problem/

 

[WileERobby]

Me ? I'd use a spread bore intake with the TQ. block EGR. Case closed.

 

[70bigblockdodge]

79 440 truck carb, except for the weird fuel inlet it's a good one.
Secondary jets may be smaller, but can always be drilled larger.

 

[pnora]

79 440 truck carb, except for the weird fuel inlet it's a good one.
Secondary jets may be smaller, but can always be drilled larger.

Just remember there were no 440's built after 1978. Yes you will find them in 79 or 80 model common motor home chassis but they were truly 1978.

 

[70bigblockdodge]

Just remember there were no 440's built after 1978. Yes you will find them in 79 or 80 model common motor home chassis but they were truly 1978.

9247 is listed that way on the guide. It probably is from a motor home hence the oddball fuel inlet. Does not necessarily mean a Dodge truck just a 440 in a truck chasis

 

[pnora]

9247 is listed that way on the guide. It probably is from a motor home hence the oddball fuel inlet. Does not necessarily mean a Dodge truck just a 440 in a truck chasis

I understand what you are saying. My point is you wont find OEM factory parts manuals supporting 1979 or newer 400 or 440 big blocks.

 

[70bigblockdodge]

I understand what you are saying. My point is you wont find OEM factory parts manuals supporting 1979 or newer 400 or 440 big blocks.

The dummies at any dealership near me could not find their *** with both hands. Support for stock replacement TQ parts is digging deep in a well that has been barely moist for a long time.
$5, $10, $20 dollar swap finds are the source parts. There is just some numbers that are parts carbs, and there are some that are base building units. That was my point.

 

[Thrashingcows]

I love the TQ carbs and run one on the 440 in my wagon, I went with an aluminum Edelbrock spread bore intake. And have several used/swap meet/Junk yard TQ's for spare parts.

 

[GTX JOHN]

The late Thermoquad will flow better than 178 with an adapter.
Put .137 jets in secondary and a 750 Air Door opening.

If you want to see a stock 400 big block with stock manifold/Thermo
running low 11's

Google John Irving Drag Racer
Green 73 Roadrunner @ 3,800 Lbs.

 

[Big bill]

I have a few carbs for sale plus sone parts carbs if anyone is interested pm me .

 

[moparbud66]

Hey all,

I recently picked up a ‘69 casting 2806178 intake for my ‘78 440 and I’m in the process of putting my C4-TQ thermoquad carb on it. I stumbled into the problem that the carb bolt holes do not line up at all. Is there an aftermarket spacer I can use to fit this carb on the earlier intake? Or do I need a whole new carb? I’d like to keep the carb since I already bought the rebuild kit, but if I have to get another one, which one should I get? Not trying to spend too much on one since I plan on making some performance upgrades to the engine later this year (intake, cam, heads, pistons, etc).
Carb: C4-TQ 9247S
Original intake: 3830733
‘69 intake: 2806178

I used the original base gasket to show how the carb would fit on the original intake and the ‘69 intake.

Any help is appreciated. Thank you!

Chris

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I have a TQ intake if you need one. Cheap, but shipping could be another story.