1966 Calais Posted January 12 Share Posted January 12 I have a 1963 Riviera 401 dynaflow. I want to purchase an orignal caburetor. I have found two numbers out there. Shop manual number is 3503s. I see in forums etc, number 3508 for my car as well. Which one is correct for my application? Thank you Bob Link to comment Share on other sites More sharing options...
Riviera63 Posted January 12 Share Posted January 12 4 hours ago, 1966 Calais said: I have a 1963 Riviera 401 dynaflow. I want to purchase an orignal caburetor. I have found two numbers out there. Shop manual number is 3503s. I see in forums etc, number 3508 for my car as well. Which one is correct for my application? Thank you Bob The Carter number is 3503S in the Master Chassis Parts Book for 401 with automatic. It also lists a 3578S for 425 with automatic. The 1963's with automatic also came with the Rochester 4GC which is number 7023143. These may be easier to find. I have a Rochester on my 1963 and have no complaints. If you want the full scoop on both carbs talk to Jon aka "carbking" on the forum. He will answer phone calls on Monday & Tuesday 9-4 central time, 573-392-7378. He will give you an unbiased report on them both. I have done this and he is very forthcoming and informative. Bill Link to comment Share on other sites More sharing options...
RivNut Posted January 12 Share Posted January 12 The 3503 is correct. I’m betting in the post that said 3508, someone just read the number wrong - bad angle, poor lighting, near sighted. Link to comment Share on other sites More sharing options...
XframeFX Posted January 12 Share Posted January 12 6 hours ago, 1966 Calais said: Shop manual number is 3503s. I have a spare 3503 for 33 years but stored it in my garden shed and now both shafts are stuck. I've seen a used toaster oven at Re-Store for $10. Maybe I'll pick it up, strip down the 3503 and bake it! The seized shafts might free-up. I drove this AFB with NO problems at one time. Unfortunately, only good for parts the way it sits now. What carburetor is on your 1963 Riviera now? If it runs well, why change? Desire to be numbers correct? Agree, #3508 must be a Type-O for 3503. I noticed your handle: "1966 Calais". It so happens I rescued a Carter AFB 3655 from a 1966 Cadillac at the wreckers on Black Friday discount deal. Very odd in that it has smaller 1-7/16" primary bores for the Big 429 cu. in Cadillac? The 3503 has 1-9/16" primaries Link to comment Share on other sites More sharing options...
telriv Posted January 12 Share Posted January 12 John, I CAN rebuild it. Can't tell you how many I've done. Unfortunately takes LOTS of time which= $$$. Caution: DON'T break the throttle shaft screws adds unnecessary consequences & additional problems. Soak in a mixture of Acetone & trans. fluid to try & free the shafts along with the heat. Tom T. 1 Link to comment Share on other sites More sharing options...
1966 Calais Posted January 12 Author Share Posted January 12 I have a Rochester on it ( not original to car). Car has 46,000 original miles former aaca senior car. I have kick down issues. takes many attempts to get it down to idle. Also, transmission bangs when applying reverse even though idle is low. Link to comment Share on other sites More sharing options...
carbking Posted January 13 Share Posted January 13 As stated by others, the 3503s is the correct carb. In the "for what its worth" category (a.k.a. worthless trivia), Carter did not assign either 3508 or 3509 to a carburetor. Jon 1 2 Link to comment Share on other sites More sharing options...
Turbinator Posted January 13 Share Posted January 13 (edited) 20 hours ago, 1966 Calais said: Which one is correct for my application? Thank Bob, as a friendly heads up buying a core carb with part numbers you want is the first step. Because you have a core carb with the identifying numbers you want does not mean it can be reasonably rebuilt. By accident I was supplied a core carb that could not be rebuilt. From now on if and when I buy a core to be rebuilt Ill ask the seller if the core CAN be rebuilt. I can say without hesitation Tom Telesco rebuilt my Carter AFB and tuned my engine to run in outstanding way. The carb was rebuilt, electronic ignition, updated plug wires, Bosch Platnum spark plugs, distributor cap all installed and adjusted by Tom made the nailhead run real good. My participation was mechanics helper. I give Tom credit for his superior work and friendly ways. I dare say there are precious few that have Tom’s mechanical skill. As far as getting along and working together both of us are fairly miserable.. LOL. Good luck Turbinator Edited January 13 by Turbinator (see edit history) 1 1 Link to comment Share on other sites More sharing options...
XframeFX Posted January 13 Share Posted January 13 9 hours ago, Turbinator said: By accident I was supplied a core carb that could not be rebuilt. 22 hours ago, telriv said: I CAN rebuild it. Can't tell you how many I've done. Unfortunately takes LOTS of time which= $$$. Bob, according to Tom concerning my stuck 3503 AFB, "I CAN rebuild it". 1) I wonder what was the issue on that core that it couldn't be rebuilt? How about salvaging the base to retain that 3503 stamping? 2) I wonder if a similar issue with my inconsistent AFB 3) I stripped down my stuck AFB to bake in a $10 toaster oven but it doesn't Fit. The air cleaner stud is STUCK as well! Link to comment Share on other sites More sharing options...
gungeey Posted January 13 Share Posted January 13 Wow! That's a killer deal by John for a correct unit gone thru by Carmen 1 2 Link to comment Share on other sites More sharing options...
Riviera63 Posted January 13 Share Posted January 13 3 hours ago, Jolly_John said: Don't know if this would interest any of the guys posting on this thread....But, I have a RESTORED (not just rebuilt) Carter AFB carb available for 1963 BUICK. It's a Carter 3578S, which, as noted earlier in this thread, is for the '63 425 cu. in. engine. This carb was never used for the project I was working on at the time, and has been sitting unused, in the original shipping box ever since. Rebuilt and restored by the well-respected BUICK craftsman and vendor, Carmen Faso. This carb started out as a good condition, in-service Carter AFB 3578S on a '63 that was being driven. Then, Carmen worked his magic. I just shot some quick pictures, as seen below. Can take better photos for someone who is interested in a possible purchase. $400, plus the shipping. Thanks. John PM sent Link to comment Share on other sites More sharing options...
RivNut Posted January 14 Share Posted January 14 (edited) Chances are if you look at the specs for both carbs, you’ll find a difference of a couple of thousandths in diameter of the secondary metering rods or something similar. I drove my ‘64 Riviera (425) with an AFB from a ‘64 ??? with a 401. I don’t know if I could have told a difference from the driver’s seat. For a totally restored CORRECT carburetor, that is a good deal. Edited January 14 by RivNut (see edit history) Link to comment Share on other sites More sharing options...
Jolly_John Posted January 14 Share Posted January 14 12 minutes ago, RivNut said: Chances are if you look at the specs for both carbs, you’ll find a difference of a couple of thousandths in diameter of the secondary metering rods or something similar. You are correct, Ed. I believe I looked this up some time ago, and found only an extremely minor difference between the jetting on the two Carter AFB's used on our '63 BUICK's. Thanks for commenting. John Link to comment Share on other sites More sharing options...
Turbinator Posted January 14 Share Posted January 14 7 hours ago, Jolly_John said: interested in a possible purchase. $400, plus the shipping. Thanks. John John, a fine offering for sure. I do not need the carb. Id just like say thank you for having the presence of mind to make the carb available. Someone Im sure would like to have that carb. Turbinator Link to comment Share on other sites More sharing options...
Jolly_John Posted January 14 Share Posted January 14 Thank you for the kind words, Turbinator. And, hats off to you for all of your helpful posts and the parts you've made available over the years! Gotta love these BUICK's! John Link to comment Share on other sites More sharing options...
RivNut Posted January 14 Share Posted January 14 (edited) I looked in my ‘63 chassis manual for a descriptions of the different AFB carburetors for the 1963 and 1964, but as we all know, there was no 425 until late December of 1963. The chassis manual was probably prepared months prior to that so the manuals would be in the dealerships when the 1963s arrived in September. There was not a description of the AFB in the ‘63 manual like there is in the ‘64 manual. Here’s a picture of the page from the 64 chassis manual that shows the comparison of the AFBs for the 401 and the 425 for 1964. Almost identical except for a couple of things. It looks like it would be easy enough to swap the 425 parts for the 401 parts if that were a real concern. Edited January 14 by RivNut (see edit history) 2 Link to comment Share on other sites More sharing options...
telriv Posted January 14 Share Posted January 14 (edited) Although many things are/remain the same it would be difficult to make the idle discharge ports smaller. It's easy enough to change metering rods. Tom T. Edited January 14 by telriv (see edit history) 1 Link to comment Share on other sites More sharing options...
XframeFX Posted January 15 Share Posted January 15 (edited) On 1/13/2024 at 12:19 PM, Jolly_John said: It's a Carter 3578S, which, as noted earlier in this thread, is for the '63 425 cu. in. engine I've been going around in circles addressing Idle and primary circuits in my 3503 for a 1963 401. Carter P/Ns for the metering rods and jets are #16 and #120 respectively. The latter appears the same for both, the 401 and this 3578 for the 425 cu. in. application. So as Tom mentioned, easy to change the rods as required. There are other minor differences such as in the idle circuit as mentioned. I have experimented with metering rods from several other AFBs including a spare 3503 which has metering rods #16-167 that appears to be meant for the 3578 AFB not the 3503. Who knows, maybe a rebuild in my carburetor's distant past has piston springs from a Papermate ballpoint pen as well? So John's 3578 AFB is RESTORED not just REBUILT which should be the best of the best. However, during a rebuild, an AUDIT should be included along with a COMPLETE dismantling of the Unit. Not just dunking it in a solution, throwing in a NAPA Carb Kit and a spray can of silverish paint once assembled. At this point, I'm yearning for a GOOD carburetor that's ready-to-run straight out of the box! Edited January 15 by XframeFX (see edit history) Link to comment Share on other sites More sharing options...
Dundee Posted January 17 Share Posted January 17 On 1/14/2024 at 6:19 AM, Jolly_John said: Don't know if this would interest any of the guys posting on this thread....But, I have a RESTORED (not just rebuilt) Carter AFB carb available for 1963 BUICK. It's a Carter 3578S, which, as noted earlier in this thread, is for the '63 425 cu. in. engine. This carb was never used for the project I was working on at the time, and has been sitting unused, in the original shipping box ever since. Rebuilt and restored by the well-respected BUICK craftsman and vendor, Carmen Faso. This carb started out as a good condition, in-service Carter AFB 3578S on a '63 that was being driven. Then, Carmen worked his magic. I just shot some quick pictures, as seen below. Can take better photos for someone who is interested in a possible purchase. $400, plus the shipping. Thanks. John That’s a beauty! If it were good for a 63 401 it would be very tempting even from down here. God knows where my original (Rochester) went so will look to work with the 650 Holley that was with the car! A long way from putting fuel through anything yet so have time to think about options as they are presented. 1 Link to comment Share on other sites More sharing options...
1966 Calais Posted January 19 Author Share Posted January 19 Unfortunately, I saw Johns post, regarding his beautiful carb too late! It would of solved my issues and then some. Link to comment Share on other sites More sharing options...
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