Carburetor choice for 472?

Dan Comoss

Dan Comoss

PCS Member
I have been fighting carburetors since I got my coach. I received the car with a 600 Edelbrock. Transmission and anti dieseling switches were not hooked up. Nowhere to attach them to the carb.

I had my mechanic find two quadrajet, one from a 75 caddy, one from a late 70's Chevy pickup. We rebuilt both of them but neither of them ran correctly. Wanting to die at low rpm and kickdown, and anti dieseling did not match up either.

I put the Edelbrock back on, purchased an adapter plate with the 4 port rather than one big open port. I managed to get it to idle and run. Still no kickdown, still in the process of tinkering with the choke. So far the only issue I have is after it's hot and sits it does not want to start easily. If I hold the petal to the floor it will fire up then sputter and choke until it clears itself out. With some reading this seems to be a common issue with Edelbrocks.

I did come across a 72 Cadillac quadrajet that was rebuilt by Autoline. It's still in the plastic wrap and box. It's $450 which seems a bit pricy, but the numbers on the carb do match for a Cadillac qj.

I was also pondering a new Holley spreadboar since it would bolt directly to the intake without a spacer.

I'm leaning toward the QJ since it would be keeping everything original. The new Holley is similar in price. What does everyone think the best option would be? Is there another option that may be better than those two?
 
There is a man in Arizona that does great work on the Quadrajet carburetors. There is no one better. He likes to have you send the distributor with the carburetor, so he can reset the ignition curve on his Sun Distributor Machine. He might even have a rebuilt unit on the shelf. He will need the year, make, engine size, and possibly a few other items to look it up.

Bruce in Peoria Arizona.
Carburetors Unlimited
7942 W Gold Dust Ave #1
Peoria, AZ 85345
623-388-0990
 
I purchased the remanned QJ last night from ebay. Pretty much every place I researched They charge between $50-$100 for a core or want your old QJ to rebuild. Since most places want at least $200 for a rebuild, more depending on what they find, plus the cost of the core. Then add $15-$20 shipping each way and a week or two turn around. I figured this was the least stressful and cost effective once I broke the math down.

Here is my next partial predicament. Since the original style QJ will be put on I will be reinstalling the Transmission Kickdown Switch and Idle Stop Solenoid. My kickdown switch seems to be in good shape, The arm is good and seems to trigger correctly with an ohm meter when turned to about 60%, I can also hear a "click" at that point!

The Idle Stop Solenoid is another issue. The rear of it with the wire is missing. I will need to find a replacement. I have been scouring the internet not finding an exact match. Nothing whatsoever! Like everyone told me before, some parts are no longer available and you need to improvise. I found one that I think will do the job. It's for an Olds 72-74 It appears the threaded area on this one is shorter and the shaft does not come out of the rear of the solenoid. Aside from shelling out a $325 for a NOS one I haven't see many other options.

I am also a bit confused of its actual function. The 72 shop manual states it as an anti dieseling solenoid. Other places say it is a fast idle solenoid for when the AC is running. Is this more of a jack of all trades switch? Would there be much of an issue If I ran the car without this until I came across a better priced one?

The closest option i have found that isn't $300 +.
www.carburetion.com

CUD4675 - SOLENOID-Carburetor Idle Stop

CUD4675 - SOLENOID-Carburetor Idle Stop
www.carburetion.com
 
They were used for both jobs depending on what the car needed but most were toup the idal with the ac on. The dash pot was used as the antie deseling device.
 
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