Holley spreadbore DP on small block
Thread Starter
Racer
Joined: Apr 1999
Posts: 422
Likes: 3
From: Oxford MI
Holley spreadbore DP on small block
Does anyone run a Holley spreadbore double pumper on a small block? I have replaced my Q-jet with this carb and now need to find an air cleaner solution as the original open element base does not clear the double pump lever.
Burning Brakes
Joined: Sep 2009
Posts: 1,124
Likes: 140
From: Western New York
I ran a Holley 650 Spreadbore double pumper on my '72 with base 350 for quite a few years. It was a Holley #6772 which was a direct replacement for the quadrajet and used the original air cleaner, which is the dual snorkel model.
A few years ago, I switched over to a Holley DP 4776 which is a square bore carb. I had to change the fuel inlet line and also the air cleaner. I run a Moroso air cleaner (don't know the number) and it's a dropped base design. It's made for the Holley and has the base that fits over the fuel bowls. If I recall correctly, it originally came with a 4" tall filter element that didn't fit, so I went to a K&N 3" tall filter that fits under my hood with just maybe a 1/4 to 1/2 inch of clearance. Hope this in some way can help you out. I was fortunate when I did the switch because I have a good speed shop about 2 miles from my home and was able to try everything right there. If you have to mail order, good luck.
Duane
A few years ago, I switched over to a Holley DP 4776 which is a square bore carb. I had to change the fuel inlet line and also the air cleaner. I run a Moroso air cleaner (don't know the number) and it's a dropped base design. It's made for the Holley and has the base that fits over the fuel bowls. If I recall correctly, it originally came with a 4" tall filter element that didn't fit, so I went to a K&N 3" tall filter that fits under my hood with just maybe a 1/4 to 1/2 inch of clearance. Hope this in some way can help you out. I was fortunate when I did the switch because I have a good speed shop about 2 miles from my home and was able to try everything right there. If you have to mail order, good luck.
Duane
Drifting
Joined: Mar 2014
Posts: 1,742
Likes: 276
From: Akron OH
I have a Holley spreadbore (List 6210) on my '71 SB and use an Edelbrock 14" round open element air cleaner. I don't have the model#, but I think it is their Pro-Flow series.
Last edited by AkrHack; Mar 8, 2015 at 09:15 PM.
Le Mans Master
Joined: Oct 2010
Posts: 6,930
Likes: 845
From: melbourne florida
2023 C3 of the Year Finalist - Modified
the factory air cleaner should fit. i have used that carb a few times and the will run very well if set up properly. they are different from a regular holley but still a good unit.
Team Owner
Joined: Sep 2006
Posts: 31,235
Likes: 4,325
From: Westminster Maryland
Hi,
I used a Holley SB/DP for many years on my 71 sb.
The problem with fitting a stock open air cleaner or a stock closed dual snorkel air cleaner is that the lever for the rear accelerator pump hits the elbow coming out of the air cleaner base for the crankcase breather connection.
You can remove the elbow from either of the 2 stock air cleaner bases or use an aftermarket open air cleaner base. You need to make a decision on how to deal with the breather then.
I remember reading that the arm can be bent to clear the elbow but I didn't see how that could be done.
Regards,
Alan
Aftermarket 14"
Dual Snorkel
I used a Holley SB/DP for many years on my 71 sb.
The problem with fitting a stock open air cleaner or a stock closed dual snorkel air cleaner is that the lever for the rear accelerator pump hits the elbow coming out of the air cleaner base for the crankcase breather connection.
You can remove the elbow from either of the 2 stock air cleaner bases or use an aftermarket open air cleaner base. You need to make a decision on how to deal with the breather then.
I remember reading that the arm can be bent to clear the elbow but I didn't see how that could be done.
Regards,
Alan
Aftermarket 14"
Dual Snorkel
Thread Starter
Racer
Joined: Apr 1999
Posts: 422
Likes: 3
From: Oxford MI
Thanks everyone. Alan71 hit my problem on the head. The base does not clear the pump lever on the secondary accel pump. I have ordered a replacement base thinking I could relocate the vent tube to a more forward location as I see a flat spot in the stamping that looks like it may have been an alternate location at some point. I was hoping others may have already solved the problem. wish my engine bay looked as clean as Alan's.
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Melting Slicks
Joined: May 2006
Posts: 3,438
Likes: 41
From: Raleigh NC
St. Jude Donor '13-'14
Thanks everyone. Alan71 hit my problem on the head. The base does not clear the pump lever on the secondary accel pump. I have ordered a replacement base thinking I could relocate the vent tube to a more forward location as I see a flat spot in the stamping that looks like it may have been an alternate location at some point. I was hoping others may have already solved the problem. wish my engine bay looked as clean as Alan's.
The previous owner of my '69 had this problem. It had a 6210 on it, and he had cut the elbow off and welded it in a different location. Looks like he even welded in a bottle cap in the old location
It is not the finest of work, his name may have been Bubba. I switched back to the original quadrajet set up and a correct air cleaner base. I do believe I have the old base around if you are interested. You will still be able to connect your breather to your valve cover.
Team Owner
Joined: Sep 2006
Posts: 31,235
Likes: 4,325
From: Westminster Maryland
Hi KV,
I think in the case of the engine shown in your picture the air cleaner was scared into submission by the hp sticker on the air cleaner's lid.
Regards,
Alan
In reality the elbow for the crankcase breather appears to be further around toward the distributor which allows it the clear the accelerator pump arm.
I think in the case of the engine shown in your picture the air cleaner was scared into submission by the hp sticker on the air cleaner's lid.
Regards,
Alan
In reality the elbow for the crankcase breather appears to be further around toward the distributor which allows it the clear the accelerator pump arm.
