Correct Holley carb for a '71 454?
10-06-2003, 08:56 PM
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Correct Holley carb for a '71 454?
I'm looking to replace the old '68-'69 Holley carb that is now on the stock LS-5 engine. The previous owner suggested I rebuild it, but I would rather just replace it. Is this the correct replacement carb for the Rochester Q-Jet that came on a '71 454? If not, what is the part # I should be looking for? Thanks in advance.
http://www.holley.com/HiOctn/ProdLin.../0-80555C.html
http://www.holley.com/HiOctn/ProdLin.../0-80555C.html
10-06-2003, 10:04 PM
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Re: Correct Holley carb for a '71 454? (bgrice)
According to my Vette Vues book, the 71 454-365hp had a Q-jet, the 454 -425hp had a vacuum secondary Holley 800 dual feed. I would say rebuild the Q-jet and enjoy one of the best carbs out there. May not be as cool looking as a big Holley, but from what I have seen its hard to beat a well turned Q-jet.......
10-06-2003, 11:00 PM
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Re: Correct Holley carb for a '71 454? (467-Ratman)
467-Ratman,
There is already a Holley carb on this engine, so rebuilding a Q-Jet is not an option. And I believe that it is a '68 date coded 4175 carb, but I may be wrong. It seems I looked it up on the internet somewhere, but I can't find it tonight. Here's the numbers on the front of the bowl that are stamped in.
Top- 30555
Bottom- 2448
And a pic below showing the threaded rods on each side of the carb. Looks old to me compared to the new designs. :lol:
There is already a Holley carb on this engine, so rebuilding a Q-Jet is not an option. And I believe that it is a '68 date coded 4175 carb, but I may be wrong. It seems I looked it up on the internet somewhere, but I can't find it tonight. Here's the numbers on the front of the bowl that are stamped in.
Top- 30555
Bottom- 2448
And a pic below showing the threaded rods on each side of the carb. Looks old to me compared to the new designs. :lol:
10-06-2003, 11:35 PM
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Re: Correct Holley carb for a '71 454? (bgrice)
You're right the correct carb for a 71 454 (425 hp) is the Holley 4150, according to the Corvette Black Book, the correct number for the carbs are as follows:
Holley R4802A #3986195 454ci, 425hp mt
Holley R4803A #3986196 454ci, 425hp at
The correct carb for your car is actually a Q-jet, either #7041204 at or #7041205 mt.
The 4150 you have is a good carb, but the 4175 is probably more of a racers carb.
Holley R4802A #3986195 454ci, 425hp mt
Holley R4803A #3986196 454ci, 425hp at
The correct carb for your car is actually a Q-jet, either #7041204 at or #7041205 mt.
The 4150 you have is a good carb, but the 4175 is probably more of a racers carb.
10-07-2003, 12:16 PM
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Re: Correct Holley carb for a '71 454? (Smokehouse69)
4150 and 4160's are not spreadbores... 4175'a are.
4150 and 4160's are "square bore" carbs... won't fit on a spreadbore (Q-Jet) manifold without an adapter.
Look on the air horn (not the fuel bowl) for "LIST nnnn" to ID the carb you currently have.
If it is a OEM Holley (installed by GM) it should also have a GM part number on the air horn.
The carb currently on the car looks like a spreadbore.
In my opinion, 650 CFM is too small for a 454.
I have the Holley LIST 6211 800 CFM spreadbore on my 70 LS5 with a 1968 Aluminum GM spreadbore Corvette manifold.
4150 and 4160's are "square bore" carbs... won't fit on a spreadbore (Q-Jet) manifold without an adapter.
Look on the air horn (not the fuel bowl) for "LIST nnnn" to ID the carb you currently have.
If it is a OEM Holley (installed by GM) it should also have a GM part number on the air horn.
The carb currently on the car looks like a spreadbore.
In my opinion, 650 CFM is too small for a 454.
I have the Holley LIST 6211 800 CFM spreadbore on my 70 LS5 with a 1968 Aluminum GM spreadbore Corvette manifold.
10-07-2003, 09:30 PM
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Re: Correct Holley carb for a '71 454? (Tom454)
Tom,
I searched through Jegs & Summit and neither offer the 6211 Holley carb. Do you think it was in such low demand that it was completely discontinued? And are your running an electric choke on your carb? Below is the opposite side of the carb I now have on the engine. I still haven't figured out what Holley carb this is as the stamped info on the front airhorn(I said bowl before) is...
Top 30555 (of B0555)
Bottom 2448 (Isn't this supposed to be the date code? Doesn't make sense if so)
I searched through Jegs & Summit and neither offer the 6211 Holley carb. Do you think it was in such low demand that it was completely discontinued? And are your running an electric choke on your carb? Below is the opposite side of the carb I now have on the engine. I still haven't figured out what Holley carb this is as the stamped info on the front airhorn(I said bowl before) is...
Top 30555 (of B0555)
Bottom 2448 (Isn't this supposed to be the date code? Doesn't make sense if so)
10-08-2003, 01:48 PM
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Re: Correct Holley carb for a '71 454? (bgrice)
It's probably an 80555 model 4175 Q-Jet/ThermoQuad replacement 650 cfm carb.
You can find the 80555C in Holleys Numerical Listing section at Holley.com
The 6211 does not have provisions for an electric choke, plus it has mechanical secondaries. In my case, it doesn't matter because my car will start in any weather without a choke. But most people (engines) need the choke.
That carb can be rebuilt, but I still think it is too small for an LS5 unless you are concerned about gas mileage.
Duh... I just looked at your first post... you already had it nailed.
So... it is not the "correct" or OEM carb.
I didn't double check the Black Book numbers posted above... but they are probably correct.
[Modified by Tom454, 1:52 PM 10/8/2003]
You can find the 80555C in Holleys Numerical Listing section at Holley.com
The 6211 does not have provisions for an electric choke, plus it has mechanical secondaries. In my case, it doesn't matter because my car will start in any weather without a choke. But most people (engines) need the choke.
That carb can be rebuilt, but I still think it is too small for an LS5 unless you are concerned about gas mileage.
Duh... I just looked at your first post... you already had it nailed.
So... it is not the "correct" or OEM carb.
I didn't double check the Black Book numbers posted above... but they are probably correct.
[Modified by Tom454, 1:52 PM 10/8/2003]
10-08-2003, 03:23 PM
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Re: Correct Holley carb for a '71 454? (Tom454)
The last carb(Q-Jet) I had rebuilt locally cost a little over $200 and it came with a disclaimer, so I'll just opt for a new Holley. I've got e-mail into both Jegs & Summit to see what they say about what should go on this engine, but I'm not looking for TOO much carb as to where I've got to keep it continually tuned. I'm in the driving mode.... not the fixing mode. :yesnod:
10-08-2003, 03:25 PM
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Re: Correct Holley carb for a '71 454? (bgrice)
And I want my 13 posts I lost in this transistion period to the new servers.
Make that *12*.... FREEBIE! :cheers:
Make that *12*.... FREEBIE! :cheers:
10-08-2003, 05:06 PM
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Le Mans Master
Re: Correct Holley carb for a '71 454? (bgrice)
Ahhh..... I see.... $200...
Hope they at least gave you a kiss after having s e x with you.
Carburetors are simple to rebuild. Too bad you don't live near me... we could do it just for fun.
I did MELVINS tripower for fun.
:)
Hope they at least gave you a kiss after having s e x with you.
Carburetors are simple to rebuild. Too bad you don't live near me... we could do it just for fun.
I did MELVINS tripower for fun.
:)
10-08-2003, 05:45 PM
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Re: Correct Holley carb for a '71 454? (bgrice)
the correct carb for your 1971 454 365 hp is a Q jet # 7041205 or 204 if A/T :chevy
[Modified by clem zahrobsky, 5:49 PM 10/8/2003]
[Modified by clem zahrobsky, 5:49 PM 10/8/2003]
10-08-2003, 05:59 PM
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Re: Correct Holley carb for a '71 454? (bgrice)
...and the carb you show in the photos is an aftermarket spread-bore Holley replacement for the Q-Jet - it's not a square-bore. I may have a forum-donated rebuildable '72 Q-Jet that would work well on your car - let me know if you're interested - it would bolt right up to your manifold.
10-08-2003, 07:28 PM
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Re: Correct Holley carb for a '71 454? (Tom454)
Ahhh..... I see.... $200...
Hope they at least gave you a kiss after having s e x with you.
Hope they at least gave you a kiss after having s e x with you.
Something I forgot to mention in this thread.... and that's "Why I am looking to replace the carb?" Maybe it's not the carb at all that is making things act up, but it sure seems that way. This is a 4 speed 454 by the way and thanks to those who posted the correct Q-Jet # for that application. The reasons behind the change are:
1)The engine starts right up with just a half pump of the throttle even after a week of sitting up and correctly goes on the electric choke. But, even after warming the engine up it takes numerous times to get it to kick off of that choke and then it goes down in stages.
2)Sometimes when it starts there is a miss/motoring sound and any attempts at giving some gas will cause backfires. I can turn it off and start it again and it will run fine. Something sticking?
3)I went out driving Monday night after work and one time the engine RPM's increased while at idle and then 10 minutes or so later I pulled to a light and the engine barely sounded like it was running.... like starving for gas. I turned it off and restarted and it went right back to normal.
Carb problems? I front outer bowl has a sticky lacquer gas substance on it, so I have to assume the inside is probably the same that may be hindering it working right. I am not going to drive this vette anymore the way it is. If it's the carb I'm going to change it.
