71HO454

Here goes.. When I obtained my 1971 LS5 it was virtually unmolested under the hood. Correct dizzy (Even the coil was a 70's replacement), alternator, etc. etc. etc. Everything was in place, or so I thought. Fast forward to today.. The engine (All numbers match) is out of the car and in storage. When checking the carburator I decided to run the number to see if it was correct. 7041205 was the number I was looking for per my NCRS manual. Low and behold, it's not that number on the carb.. The number I have is 17054917 I'm thinking how can all these parts be numerically correct except the carb. So I decide to look up the carb number on the net (Pain in the ***) to see what it is. I finally find a site that says it's a service replacement for a 1971 402ci-454ci Pass Vehicle. Hmmmmm! 1971, same as the car.. coincidence?

With everything except the carb correct and molested under the hood, is it coincidental that someone along the way swapped my correct carb for a date specific (1971 402-454) carb? I'm stumped...

Sorry for the long post.. Any opinions would be welcome!!

Bo5co

Well that's interesting: http://www.carburetion.com/Kits/chevy.htm

Down near the bottom of that page - 1971 402", 454" ENG 17054917 ROCHESTER 4MV

I had always thought that the "170' meant is was built after 1975

airtime

http://forums.corvetteforum.com/c3-t...ld-thread.html



here is a link to my 71 ls-5 thread. 63 mako gave some pretty good advise on my carb. he may be able to help you out. pm him if he doesn't post here. i got an original 71 ls-5 q-jet off a ls-5 71 chevelle on the shelf. i think they are the same but not sure. i am using a smi custom 800 cfm q-jet with electric choke that is set up for my engine. the breif period the 71 ls-5 chevelle carb was on my car it ran better than the one that was on it when i bought it.

7T1vette

With all those 'puppies' to choose from on the engine assembly line, it wouldn't surprise me that they installed that Q-Jet...if the one they needed was out-of-stock. It is a 454 Q-Jet. Back then, if it fit, they shipped it.

71HO454

Thanks guys.. I appreciate the insight.. I just checked a site called The Carb Doctor and they show that part number as a "Service Replacement"

•Service replacement numbers: 17050507 - 17055888

airtime

i think sometimes the restoration crowd forgets that back in the late 60's and early 70's (and present day i'm sure) alot of stuff was not done By the Book. this custom 800 cfm q-jet i have now. it is off a 75, 76 stock 350 corvette. guess GM had some extra carbs they were trying to get rid of and stuck them on the corvettes.

71HO454

I agree with this statement...

I just wonder why the carb I have is numerically correct for a 1971 454 and how much does this affect the value of it?

Faster Rat

By about the amount it would cost to find & buy the correct carb, in restored and good operating condition with an acceptable date stamp.

gq82

Service replacement means over the counter dealer supplied/installed and would not be available as a production (factory installed) piece.

Mike Ward

This carb is not original to the assembly line, it's an over the counter service replacement. Have you got the date code handy to get an idea when it might have been swapped?

lars

Your carb is a Service Replacement carb - it is not numerically correct for a '71. Service replacement carbs were produced after the original carbs were out of stock. Your carb was produced after 1975 and is the "correct" replacement carb for the '71. It's not a '71 carb, but identical to it, and it's the carb that Rochester built to specifically repalce the 71 BB carb. It's the best thing you can have next to the original.

Lars

71HO454

That's what I was afraid of!! Now the question is, what year did it happen and why? All we can do is speculate, and if it was much later in the decade how is the carb number specific to a 1971 big block?

Could it have been delivered to the selling dealer with the correct carb, but replaced with mine due to some mechanical issue?

71HO454

Thank you Lars!!

I may have over used the "numerically correct" slogan, being that it showed that carb number next to the 1971 box on the chart.

71HO454

Mike,

Is the date code located parallel to the carb number? If so, it's 3553

If that's not it, where would it be and I'll go find and advise..

Thanks..

Mike Ward

As Lars said, the carb could not have been built before 1975, so I believe 3553= 355th day of 1983.

71HO454

Thanks Mike


And thanks to the other guys too. Always a big help per the usual..

Ebay here I come, this carb is out of here..

7T1vette

Keep the carb you have. You may need some of those parts to make a whole 'good' one when you find another.

airtime

lars is consider here by most people to be in the "know crowd" . lol you may contact some of the custom q-jet guys around here and see if they have one or can put there hands on one. don't know if all ls-5's carbs were the same but you may lurk around on the chevelle forums and find one since they had the ls-5 starting in 1971.

airtime

only thing scary about buying a carb off fleabay is the unknown condition. q-jets are getting old and having one rebuilt by a recommended shop will be kinda expensive considering you just paid good money to buy it. try a custom q-jet builder first before you buy something you cain't use.

71HO454

Thanks guys, but the incorrect carb I have in my hands is going to be listed on ebay. I don't care what it brings. Hopefully is draws a bid... I'm buying nothing!!

I have a 780 Holley on my HO454 and to be honest.. I don't forsee the original LS5 ever going back into the car. Not in my lifetime anyway. In fact, when the HO gets tired, I'm eyeballing that ZZ502!! So I'm not going to lose one minute of sleep not having a correct carb collecting dust on the shelf. I own this car to simply enjoy, it was never an investment and it will never be thought of as one. I'm half tempted to sell all the original LS5 parts just to get them out of my garage. When they're gone, they're gone.. Problems and stress over originality solved!!

Maybe there is someone on this site that want's a correct 71 LS5 engine?? Less the carb, of course..