# Quadrajet questions and advice needed



## Cory21 (Sep 10, 2020)

Hello. Unfortunately my new gto came with some engine issues - and not a numbers matching car anyway. To shorten the story, I’m purchasing an engine from a reputable builder in Oklahoma (reputable per this forum and several others). I will get a gto block, not necessarily a 67 -gas pump compression and a little less than 400 horses. Wow. I need to source a quadrajet. Any advice? I see one on eBay for 1500 from a vendor in CA and that carb has 67 gto numbers which is nice. But, do I really care If it’s a 67? I’ve reached out a few times to Cliffs performance carbs as they are the ultimate resource but I can get a response. Looking for a gto quadrajet that will work on this new engine. Thoughts? Thanks.


----------



## PontiacJim (Dec 29, 2012)

Cory21 said:


> Hello. Unfortunately my new gto came with some engine issues - and not a numbers matching car anyway. To shorten the story, I’m purchasing an engine from a reputable builder in Oklahoma (reputable per this forum and several others). I will get a gto block, not necessarily a 67 -gas pump compression and a little less than 400 horses. Wow. I need to source a quadrajet. Any advice? I see one on eBay for 1500 from a vendor in CA and that carb has 67 gto numbers which is nice. But, do I really care If it’s a 67? I’ve reached out a few times to Cliffs performance carbs as they are the ultimate resource but I can get a response. Looking for a gto quadrajet that will work on this new engine. Thoughts? Thanks.


OK, you are not to clear on what you are wanting? Do I understand you have a 1967 GTO?

Cliff's no longer rebuilds carbs - but will do some rare/specific carbs for a few. He basically sells the parts now. 

Personally, no reason to purchase a $high dollar 1967 Q-jet when the block is not original. No one is really going to notice that the carb is not 1967 as most all Pontiac Q-jets are the same. The 1967 has a unique accelerator pump, so I would stay away from it unless you were going concours restoration and all your engine/drive line parts were original & numbers matching.

What intake? I believe the 1967 intake uses a bi-metal spring located on the intake while later carbs used the choke housing found on the side of the carb. 1967 intake also had a heat passage right under the carb and requires the correct set of gaskets. Not really a good intake per-say as it can cause problems putting too much heat into the carb and you can get fuel issues.

Next thing to look at is the carb linkages for the gas pedal. Most will work and it does not take much to make one work if it is not exact.

So most any Pontiac Q-jet carb will do. But my guess is that you don't want to rebuild one yourself and would rather purchase a ready to bolt-on and go carb? Several in the past have said SMI was a good choice. Maybe a member or to will chime in. Here is their website and you can read what they offer. Looks good to me.






Rochester 4BBL Quadrajet 800CFM for Pontiac


SMI Carburetor offers the best performing Rochester 4BBL Quadrajet 800CFM for Pontiac carburetor




www.smicarburetor.com


----------



## O52 (Jan 27, 2019)

Best Quadrajets are from the mid seventies. They had been redesigned several times by then and have electric chokes. It can be any model, just make sure its not a Chevy QJ. You want one that has the front fuel inlet (Most Buick/Olds/Pontiac). As Jim said, SMI (Sean Murphy Induction) will set you up right.

Don't know if your builder is including an intake but if not, the factory manifolds are just as good as any aftermarket street manifold. Just heavier. The manifolds are almost all the same but have minor differences or flaws between the years.
Best factory intakes are the 70-71.
67 has a hot air circuit cut into the carb mounting area requiring special carb mounting gaskets. This circuit can be plugged however.
68-69 Manifolds have a tendency to crack between the secondary venturi and the hot air crossover
72 has a different choke coil and the hot air crossover is taller requiring special intake gaskets if using 67-71 heads. 
73 and up have the EGR system


----------



## Cory21 (Sep 10, 2020)

Great advice. Thanks to both. I will call Sean today.


----------



## 1968gto421 (Mar 28, 2014)

I have a Sean Murphy )SMI) quadrajet and it is great! He asks for all the specs on your engine and drivetrain and builds acccordingly. Mine looked like a brand new Qjet when it arrived. MIne did not come with any insructions as to any tips specific to Sean's remanufacture but he guided me to his advice on his website. Here's a link, just scroll down to tuning instructions:






SMI Carburetor FAQs | Sean Murphy Induction


Frequently Asked Questions about SMI Caruburetor and Sean Murphy Induction.




www.smicarburetor.com





Hope this is helpful.


----------



## GTOmoe (Jan 13, 2009)

Cory21 said:


> Hello. Unfortunately my new gto came with some engine issues - and not a numbers matching car anyway. To shorten the story, I’m purchasing an engine from a reputable builder in Oklahoma (reputable per this forum and several others). I will get a gto block, not necessarily a 67 -gas pump compression and a little less than 400 horses. Wow. I need to source a quadrajet. Any advice? I see one on eBay for 1500 from a vendor in CA and that carb has 67 gto numbers which is nice. But, do I really care If it’s a 67? I’ve reached out a few times to Cliffs performance carbs as they are the ultimate resource but I can get a response. Looking for a gto quadrajet that will work on this new engine. Thoughts? Thanks.



Hi,

Do yourself a favor and contact Sean Murphy Induction, you'll be extremely satisfied. I have purchased three in the last 5 years for 2 GTO's 69 and 65 and 67 442. Amazing performance.


----------



## Ebartone (Aug 18, 2019)

GTOmoe said:


> Hi,
> 
> Do yourself a favor and contact Sean Murphy Induction, you'll be extremely satisfied. I have purchased three in the last 5 years for 2 GTO's 69 and 65 and 67 442. Amazing performance.


I have to agree. I started my Quadra jet project by purchasing on eBay a 17056262 For about $100. Then after about $200 in parts from Cliff, and now he is working the base plate and some other things for me including plating. I’m sure that will be another couple hundred dollars. By the time I add it all up in truth I could have probably just purchased a stage two or even stage III carburetor to begin with. I’m enjoying the journey, but not that much!


----------



## Jared (Apr 19, 2013)

So you ordered a LW 400 crate engine? How far out is the lead time on yours? I have a 455 short block on order from him that should be ready within the month.


----------



## Cory21 (Sep 10, 2020)

Thanks everyone for the thoughts and advice. Learning every day....

So I ordered a 400 long block from LW and lead time is still unclear because of his backlog. Likely before the holidays, but could run into the first half of January. I also pulled the trigger on a Sean Murphy Quadra jet and the lead time on that is 8 weeks. Sounds like Len and Sean have a loyal following here so I have high expectations! 

Oh, and I decided to go ahead and have the th400 3 speed rebuilt while I’m at it. Haven’t sprung that one on the wife yet. Prayers welcomed for when I do.


----------



## Jared (Apr 19, 2013)

I ordered mine in early July and the lead time has been a bit longer than expected. I guess Len's shop has been pretty busy this year so he is running behind. I don't mind the long lead time and would be hesitant to use a shop that had immediate availability. The shop doing the heads is also behind schedule because of storm damage so it really doesn't matter either way. The added time has given me some breathing room to spread out the orders for everything else I needed to put this all back together. At this point I'm probably going to wait until the spring to do the assembly and reinstall. The weather in NE is very unpredictable in the winter and I want to be able to break in the new engine right after it is put together not hit a very long delay due to snow. I also need to do the install outside because I don't have the height clearance to do it in the garage. The car is in backwards and the hoist doesn't clear the door.

Good luck keeping your wife on board. These projects have a tendency of becoming very expensive. Having the right partner in your corner makes it way easier. The fact that you have the car at all shows that she was at least on board that far. Fingers crossed she keeps her sense of humor about all this. I gave my wife what I thought at the time was a high ball park estimate for this project and she didn't even blink. I have to go through the receipts at some point but I think I may be slightly north of the high estimate by the time this is all finished.


----------



## Cory21 (Sep 10, 2020)

Jared said:


> I ordered mine in early July and the lead time has been a bit longer than expected. I guess Len's shop has been pretty busy this year so he is running behind. I don't mind the long lead time and would be hesitant to use a shop that had immediate availability. The shop doing the heads is also behind schedule because of storm damage so it really doesn't matter either way. The added time has given me some breathing room to spread out the orders for everything else I needed to put this all back together. At this point I'm probably going to wait until the spring to do the assembly and reinstall. The weather in NE is very unpredictable in the winter and I want to be able to break in the new engine right after it is put together not hit a very long delay due to snow. I also need to do the install outside because I don't have the height clearance to do it in the garage. The car is in backwards and the hoist doesn't clear the door.
> 
> Good luck keeping your wife on board. These projects have a tendency of becoming very expensive. Having the right partner in your corner makes it way easier. The fact that you have the car at all shows that she was at least on board that far. Fingers crossed she keeps her sense of humor about all this. I gave my wife what I thought at the time was a high ball park estimate for this project and she didn't even blink. I have to go through the receipts at some point but I think I may be slightly north of the high estimate by the time this is all finished.


Hey Jared - any update on your 455 from Len? You get it yet? My 400 is still on order. I think after the first of the year at this point ... but I need to call him tomorrow to get the latest update.


----------



## Jared (Apr 19, 2013)

Cory21 said:


> Hey Jared - any update on your 455 from Len? You get it yet? My 400 is still on order. I think after the first of the year at this point ... but I need to call him tomorrow to get the latest update.


Sorry, been off of here for a while. The 455 showed up a few days before Christmas. I just got word that the heads should be ready later this month. Looking good to get it back on the road by the spring.


----------

