Motor in and out

[Carmine]

That carb is too small for a 409 if it is truly for a 300 horse 327! You are are going to leave a lot of horse power on the table. A small block Chevy AFB will have the 4 1/8" air horn and flow about 500 cfm. You will need at least 600 cfm. That carb will have the 5 1/8" air horn and fit your dual snorkel air cleaner base.

I don't have the carb. # available as I write this, but I certainly can get it. I did research this number as to usage and it was used on the '64-'65 Corvette 327/300. I believe I also read from a flow chart that it flowed 575 cfm. I know ideally a 600 cfm would be best but I thought for time being, this would be close enough. The air horn does measure 4 1/8". I had this carb. rebuilt and on the dyno, it adjusted quite well. I'll be going to a large swap meet next month and keep my eyes open for another carb. Just wondering though, if an AFB air horn measures 5 1/8", is that a given that it flows at least 600 CFM?? Thank you, Carmine.

 

[1961BelAir427]

Carmine, I can't speak for the factory original AFB's, but the later aftermarket ones from Carter and now sold by Edelbrock all have 5 1/8" necks and can be bought in 500 cfm size. So be careful there.

I'm sure someone will post up on original equipment versions.

 

[blkblk63ss]

Wow, does the bleeding ever stop????
That's just to funny Carmine!!!!!At least you are taking it in stride. I have known some one when thing's didn't go right or could not fix some thing they would get mad and take a hammer to it and throw in in the junk and say ''There you sob ,i fixed you. {My Late father}I had seen him do that once and watching him i got a chuckle out of that , he did not see my humor!!!!!

 

[oldskydog]

The 5 1/8 AFB carbs on the 409 started with the 3270 on the 360hp engine in 61. The 2x4 carbs continued to be 4 1/8 carbs but all the solid lifter single 4 barrels used the 5 1/8.

 

[Carmine]

Thanks everyone. I just checked the number on my AFB-3721-S . This carb. was used on manual trans. '64-'65 Corvette 327/300. According to what I just read, it flows 575 cfm. A 600 cfm would be ideal but I can live with the difference of 25 cfm's for now. I bought this carb. on ebay and liked what I saw and how it was described. It was taken off an engine about 15 yrs. ago in perfect working order. Has been sitting on a shelf since. After it arrived, I took a look at it and it was very clean. Butterflies worked, all levers were free and working and all the parts were there. I was very tempted to bolt it on as is, but didn't. Had it rebuilt by a guy in the business for 40 yrs. He said it was extremely clean inside and in nice shape. I know its not the perfect carb. for my application, but I'll make do until something else comes along. Should also mention that when I was looking for one, there were several AFB-3721-S carbs. on eBay. Various prices depending on condition. I already have a 600 cfm Edelbrock 1406 w/electric choke in very good condition. I may decide to try this someday. Who knows, Carmine.

 

[Carmine]

Wow, does the bleeding ever stop????
That's just to funny Carmine!!!!!At least you are taking it in stride. I have known some one when thing's didn't go right or could not fix some thing they would get mad and take a hammer to it and throw in in the junk and say ''There you sob ,i fixed you. {My Late father}I had seen him do that once and watching him i got a chuckle out of that , he did not see my humor!!!!!

I use to act like your Dad at one time. Had very little patience for parts and things that didn't go right. I recall several times destroying perfectly good parts because I really had no idea what I was doing. By destroying it, I got instant relief of stress and anxiety. I actually felt a little bit better. But, by doing so, it also gave me the opportunity to buy another inflated price part that I really hadn't figured on. So, I had to find that very delicate balance of being annoyed and walking away before destruction. As I've gotten older, I've gotten much better with it. Is it just me or is it a way of life that everything I buy cost $500.00. I want 2 special bolts. Ok, $500.00. Alright, just one bolt. That's also $500.00. People get fixated on a price and just won't let go I guess. I think there is a conspiracy among the vendors . Anyhow, that is my very limited experience, Carmine.

 

[skipxt4]

The 2 special bolts, must have been GOLD plated, Carmine.

 

[Carmine]

Just a quick pic to show some progress. Have a few adjustments to make like shorten the choke tube. Thanks for looking, Carmine.

 

[303Radar]

Where did you get the vent tube? I like the top, even if it is a cover.

 

[skipxt4]

Why is the choke tube, that close, to the valve cover?

 

[Carmine]

Where did you get the vent tube? I like the top, even if it is a cover.

I believe I bought that at Show Cars.

The choke tube with the insulation on it, is resting right on the valve cover. Reason being, the carb. is for a '64-'65 Corvette and the choke housing is located in a different position on the carb. in comparison to the proper '62 AFB. On the proper carb. for that motor, I do believe the housing sits up higher and slightly more towards the rear. To get everything to work, I had to use a 1/2" carb. spacer so that I could thread the choke tube nut onto the housing not hitting the valve cover. I didn't know about these differences. I found out after I bought the carb. and had it rebuilt, so I was using it no matter what (at least for now).

But, it doesn't stop there. Kind of like the domino affect. Change one thing and it affects others. For example, I have the carb. sitting 1/2" plus the gasket thickness, higher then factory. Just received my new dual snorkel base to accommodate the 4 1/8 air horn on the AFB. Put that air cleaner on and it looks terrific. Just what I expected. But, might have a problem with hood clearance. I didn't try closing the hood completely. Looks tight. Had a good day in the garage and didn't want to ruin it if the fit was no good. Monday will be soon enough. I do have a Plan B though. If clearance is an issue, I'm using that great looking air cleaner and carb. regardless. They make an electric choke housing to replace the mechanical one on the AFB. So, I install the electric one and remove the spacer and choke tube. Things should fit then, Carmine.

 

[Carmine]

I closed the hood completely this a.m. and everything fit fine. The top of the air cleaner never made an impression in the insulation, Carmine.

 

[skipxt4]

About time, something worked out, in your favor.

 

[409newby]

What is the casting # on your intake manifold ? looks different from mine Pat

 

[Jim Sullivan]

 

[Carmine]

What is the casting # on your intake manifold ? looks different from mine Pat

I don't know off hand what the number is Pat, but I can take a look when I go to the garage next time. I do believe its a '65 manifold, Carmine.

 

[real61ss]

Carmine,
you need to correct the fuel line going from the pump to the carb.

 

[Carmine]

Carmine,
you need to correct the fuel line going from the pump to the carb.

That is the fuel line they sent me. I'd be more then happy to correct it, if you told me what was wrong with it. Thank you, Carmine.

 

[real61ss]

That is the fuel line they sent me. I'd be more then happy to correct it, if you told me what was wrong with it. Thank you, Carmine.

I'll send you a photo when I get home or I'm sure Paul could post one. It may be the one that Showcars sent u but like the PS pulley, you didn't install it correctly and where you have it you are going to experience vapor lock. The line should not be routed down between the water pump and the block as yous appears to be, it should stay on the outside of the pump. If you look at the photo that I sent you concerning the PB hose you can see a little of the gas line and see that it doesn't go inside the water pump.

 

[real61ss]

Carmine,
if you will visit the Super Chevy Magazine website, go to Features, look up Impala, 1961 and look at the article that Doug Marion did on my 61SS you will find a photo showing a good shot of the fuel line. Granted, this a 305 horse motor but it doesn't matter, it is a single four motor and that fuel in from the carb to the pump is NOT a repo, that is the original fuel line.