Pontiac GTO Forum banner
1 - 20 of 52 Posts

·
Registered
1967 400/400
Joined
·
2,115 Posts
Discussion Starter · #1 · (Edited)
Since I see weekly carb postings on this site, and no one seems to love Edelbrock carbs or include them in the GTO options, I figured that I'd make a post to at least enlighten folks about why this carb can be great.

First of all, Edelbrock has improved their carbs and they now have an AVS2 line. Don't assume that all Eddy carbs are AVS2. It offers a dramatically improved fuel delivery circuit, which atomizes the fuel better.

  • Edelbrock carbs won't work well with more than 6psi of fuel pressure, so include the cost of a pressure regulator or fuel pump with your purchase. The Edelbrock fuel pump has an advantage over a regulator, because it's clockable, rebuildable, high perf, and it handles ethanol.
  • Eddy carbs have no filter, so include that in your purchase, too. And while we're on the topic, they do have a brass barbed inlet, so you can just hook up a rubber hose and GO! But they also have a banjo, chrome inlet setup, which reroutes the line to a better location, and is available with an inline filter. So consider that too.
  • Edelbrock also makes a braided stainless "pump to carb" line, for Pontiac, which uses 6an fittings and will adapt directly to their fuel filter and banjo line, if you chose to go that route.
  • If your heat crossover is active and youve had issues in the past with heat, Edelbrock makes a heat insulator gasket, which is reusable.
  • Even though the secondaries are noticeably bigger than the primaries, the Edelbrock AVS2 is a SQUARE BORE carb. HOWEVER, contrary to Edelebrocks claim that "you need an adapter to mount one on a spread bore manny", YOU DO NOT. Not Only have I done it twice, but I also confirmed with Edelbrock that it's an inaccurate instruction, in their manual.
Why do I like these carbs? All areas of fuel delivery are easily tunable, without draining fuel, in less than 5 minutes. So you can separate and tweak:
  • Idle mixture.
  • Choke.
  • Off idle transition speed.
  • Off idle transition taper/ delivery.
  • Cruise.
  • Primary.
  • Secondary.
  • Air Flap.
I've been collecting and working on Pontiacs, nearly exclusively for about 35 years. During that time, the best tuners and accomplished racers who Ive met, have all agreed that Pontiac and Chevy engines arent at all alike. Carburation is a primary area where that is evident. Pontiacs nearly all accept "more fuel", than their Chevy counterparts, so don't under carb!

A 650 isn't adequate for a Pontiac 400. I run the 800 on mine and I love it. I can easily jet it down to be as economical as I wish, or open it up to fan the flames.

I'm no expert on carburation, but I do hang out with a bunch of experts and I do all of my own work, so this is from the horses ass mouth.

One thing that I'll say about pricing is: Compare apples to apples. Edelbrock carbs may appear cheaper, and maybe they truly are, but just make sure to include the cost of gaskets, pressure regulation, and lines.

A final note for anyone who's considering a Quadrajet. People have mistakenly given Quadrajets a bad name over the last 55 years. The internet set the world straight on this. Quadrajets are awesome! HOWEVER, "quality cores" are nearly non existent and parts chain rebuilds are extremely hit or miss, usually miss. Reputable rebuilders like Lars and CLiff will not even touch a parts chain rebuild. So keep in mind when you hear "Use a Quadrajet", that advice is often 15 years old when good Quadrajets were readily available.

If you insist on a Quadrajet, a reputable one will start at $800, in 2022, which it is as you read this. Not that you wont get lucky with a Summit or Amazon rebuild, but beware, very few people take a carb back once it has fuel in it.

This is the best resource that I've found for Edelbrock information.
 

·
Premium Member
Joined
·
1,194 Posts
Good Write up army, I agree with the adjustments on it because it is not that easy with the Q-Jet . A company called I5 in California makes a good Q-Jet for around $ 380
 

·
Registered
Joined
·
109 Posts
Since I see weekly carb postings on this site, and no one seems to love Edelbrock carbs or include them in the GTO options, I figured that I'd make a post to at least enlighten folks about why this carb can be great.

First of all, Edelbrock has improved their carbs and they now have an AVS2 line. Don't assume that all Eddy carbs are AVS2. It offers a dramatically improved fuel delivery circuit, which atomizes the fuel better.

  • Edelbrock carbs won't work well with more than 6psi of fuel pressure, so include the cost of a pressure regulator or fuel pump with your purchase. The Edelbrock fuel pump has an advantage over a regulator, because it's clockable, rebuildable, high perf, and it handles ethanol.
  • Eddy carbs have no filter, so include that in your purchase, too. And while we're on the topic, they do have a brass barbed inlet, so you can just hook up a rubber hose and GO! But they also have a banjo, chrome inlet setup, which reroutes the line to a better location, and is available with an inline filter. So consider that too.
  • If your heat crossover is active and youve had issues in the past with heat, Edelbrock makes a heat insulator gasket, which is reusable.
Why do I like these carbs? All areas of fuel delivery are easily tunable, without draining fuel, in less than 5 minutes. So you can separate and tweak:
  • Idle mixture.
  • Choke.
  • Off idle transition speed.
  • Off idle transition taper/ delivery.
  • Cruise.
  • Primary.
  • Secondary.
  • Air Flap.
I've been collecting and working on Pontiacs, nearly exclusively for about 35 years. During that time, the best tuners and accomplished racers who Ive met, have all agreed that Pontiac and Chevy engines arent at all alike. Carburation is a primary area where that is evident. Pontiacs nearly all accept "more fuel", than their Chevy counterparts, so don't under carb!

A 650 isn't adequate for a Pontiac 400. I run the 800 on mine and I love it. I can easily jet it down to be as economical as I wish, or open it up to fan the flames.

I'm no expert on carburation, but I do hang out with a bunch of experts and I do all of my own work, so this is from the horses ass mouth.

One thing that I'll say about pricing is: Compare apples to apples. Edelbrock carbs may appear cheaper, and maybe they truly are, but just make sure to include the cost of gaskets, pressure regulation, and lines.

A final note for anyone who's considering a Quadrajet. People have mistakenly given Quadrajets a bad name over the last 55 years. The internet set the world straight on this. Quadrajets are awesome! HOWEVER, "quality cores" are nearly non existent and parts chain rebuilds are extremely hit or miss, usually miss. Reputable rebuilders like Lars and CLiff will not even touch a parts chain rebuild. So keep in mind when you hear "Use a Quadrajet", that advice is often 15 years old when good Quadrajets were readily available.

If you insist on a Quadrajet, a reputable one will start at $800, in 2022, which it is as you read this. Not that you wont get lucky with a Summit or Amazon rebuild, but beware, very few people take a carb back once it has fuel in it.

This is the best resource that I've found for Edelbrock information.
Since I see weekly carb postings on this site, and no one seems to love Edelbrock carbs or include them in the GTO options, I figured that I'd make a post to at least enlighten folks about why this carb can be great.

First of all, Edelbrock has improved their carbs and they now have an AVS2 line. Don't assume that all Eddy carbs are AVS2. It offers a dramatically improved fuel delivery circuit, which atomizes the fuel better.

  • Edelbrock carbs won't work well with more than 6psi of fuel pressure, so include the cost of a pressure regulator or fuel pump with your purchase. The Edelbrock fuel pump has an advantage over a regulator, because it's clockable, rebuildable, high perf, and it handles ethanol.
  • Eddy carbs have no filter, so include that in your purchase, too. And while we're on the topic, they do have a brass barbed inlet, so you can just hook up a rubber hose and GO! But they also have a banjo, chrome inlet setup, which reroutes the line to a better location, and is available with an inline filter. So consider that too.
  • If your heat crossover is active and youve had issues in the past with heat, Edelbrock makes a heat insulator gasket, which is reusable.
Why do I like these carbs? All areas of fuel delivery are easily tunable, without draining fuel, in less than 5 minutes. So you can separate and tweak:
  • Idle mixture.
  • Choke.
  • Off idle transition speed.
  • Off idle transition taper/ delivery.
  • Cruise.
  • Primary.
  • Secondary.
  • Air Flap.
I've been collecting and working on Pontiacs, nearly exclusively for about 35 years. During that time, the best tuners and accomplished racers who Ive met, have all agreed that Pontiac and Chevy engines arent at all alike. Carburation is a primary area where that is evident. Pontiacs nearly all accept "more fuel", than their Chevy counterparts, so don't under carb!

A 650 isn't adequate for a Pontiac 400. I run the 800 on mine and I love it. I can easily jet it down to be as economical as I wish, or open it up to fan the flames.

I'm no expert on carburation, but I do hang out with a bunch of experts and I do all of my own work, so this is from the horses ass mouth.

One thing that I'll say about pricing is: Compare apples to apples. Edelbrock carbs may appear cheaper, and maybe they truly are, but just make sure to include the cost of gaskets, pressure regulation, and lines.

A final note for anyone who's considering a Quadrajet. People have mistakenly given Quadrajets a bad name over the last 55 years. The internet set the world straight on this. Quadrajets are awesome! HOWEVER, "quality cores" are nearly non existent and parts chain rebuilds are extremely hit or miss, usually miss. Reputable rebuilders like Lars and CLiff will not even touch a parts chain rebuild. So keep in mind when you hear "Use a Quadrajet", that advice is often 15 years old when good Quadrajets were readily available.

If you insist on a Quadrajet, a reputable one will start at $800, in 2022, which it is as you read this. Not that you wont get lucky with a Summit or Amazon rebuild, but beware, very few people take a carb back once it has fuel in it.

This is the best resource that I've found for Edelbrock information.
Specs on your 400? How do you have the 800 jetted? I'd like to try the AVS2 for my 400, but 650 sounds too small and I'm not sure on the 800.
 

·
Registered
1967 400/400
Joined
·
2,115 Posts
Discussion Starter · #4 ·
Good Write up army, I agree with the adjustments on it because it is not that easy with the Q-Jet . A company called I5 in California makes a good Q-Jet for around $ 380
Does that company have cores or do you need to supply it? That sounds awful cheap!
 

·
Registered
1967 400/400
Joined
·
2,115 Posts
Discussion Starter · #5 ·
Specs on your 400? How do you have the 800 jetted? I'd like to try the AVS2 for my 400, but 650 sounds too small and I'm not sure on the 800.
My motor is very mild:
  • Original 400 bored .030 over.
  • Ram Air cam, full roller.
  • Original 670 heads.
  • Pro billet dizzy with a custom curve.
The 800 worked flawlessly out of the box, and according to my AEM AFR Gauge, I was darn near exactly where @Lemans guy said I should be, through the range. High 12's and 13's.

I actually leaned it out into the 14's, but mostly because winter air hit right about when I installed the new cam, so it just "fell" there. I still need to reset the timing and rejet for the new cam.

The Edelbrock carbs are famous for performing well, out of the box. The 800 was no exception. The simple fact is that Pontiacs do "like gas", and the modest design of this carb makes it easy to work well for a broad range of applications. I spent a ton of time on the phone with experts when I picked the 800 AVS2. If I were to replace it with a Holley today, I'd look for an 800 or bigger. I'd rather jet a big carb down than try to sell my small carb because it was choking my engine.
 

·
Registered
1967 400/400
Joined
·
2,115 Posts
Discussion Starter · #7 ·
No core needed . I ran one on mine before I sold it, no issues. New bushings flaps the whole 9 yards View attachment 149227
I'm very surprised that no one is talking about them then. I found people willing to rebuild one for $400 but I had to supply the core. Of course there are plenty of people on summit, amazon, and eBay that are happy with their generic rebuilds, so I have no idea why cliff and Lars refuse to touch them
 

·
Registered
Joined
·
639 Posts
Specs on your 400? How do you have the 800 jetted? I'd like to try the AVS2 for my 400, but 650 sounds too small and I'm not sure on the 800.
If your 400 is relatively stock, the 650 would probably be fine unless you have your foot through the floor all the time. I had one on my 400 and never seemed to have any issues with fuel starvation. My 400 was a lower hp stock type build. I reused the same carb for breaking in my 461 because I knew it ran good on the old engine. It was fine for break in but I am going to replace it with the 800 AVS2 that Army was talking about. I actually really like the Edelbrock carbs as well and I agree with what he said. They are very tunable and typically run good right out of the box. One thing that should be checked on them before running is the float level. I had one on a Camaro that just would not run right. Turned out one of the floats was set too high. I almost suspect it was from shipping and not a manufacturing issue.

Only downside right now is they don't seem to be in stock anywhere. All of the bigger suppliers (Jegs, Summit, etc) have them listed as not available until early March.
 

·
Registered
Joined
·
639 Posts
My Holley has site glasses so I would have known about the high float level 🤣
True. Checking the float level on an Edelbrock is best done before you ever install it on the car since it needs to come off to do it anyway. You need to remove the top of the carb to do it, not something I'd risk doing on the car for fear of dropping something small into the engine. That being said, it takes about 5 minutes to do and you only need a drill bit (I can't recall the exact size right now) to use as a gauge. Like a lot of guys on here, I don't race mine so I'm not concerned about squeezing every last horse out of the stable. I use what is easiest for me since I am not a master tuner by any stretch of the imagination.

I'll add that this is a good thread Army started. These carbs don't get any love at all on here and, for years, I thought I was the only one on here running one.
 

·
Registered
1967 400/400
Joined
·
2,115 Posts
Discussion Starter · #13 ·
My Holley has site glasses so I would have known about the high float level 🤣
I love Holleys! Any of you guys who follow my ridiculous exploits know that I'll spend any amount of money on my GTO, with very little coaxing. The simple fact is that the last Holley I bought for my Vette, a 750 DP, took 6 months to be delivered. It took that long, because despite the fact that they're "Made in America", all of the parts are made overseas (so they';re merely assembled here). When it showed up, the throttle shaft was bent because the carb had been dropped. Then it was shrink wrapped and foamed, after the drop. I called Holley and they acted like I shouldve been grateful that I got one.

Do you think I had a problem with this? Nope. I had a problem with the fact that it's the most expensive carb you can buy. I don't mind paying a premium, but I demand premium products in exchange.

At the end of the day... I love working on my GTO and tuning and dialing it in. If I had to do 2 complete changes on the idle, primary, mid, and mains of a Holley, in one day, I'd be aggravated. All of those gaskets, all of the split fuel, all of the time invested, just to do it all again when the season changes. With the Eddy, there are no gaskets to change, no fuel to spill, and Im done in minutes. One is fun, one sucks.

Lets face it, would you rather change the gears in a BOP on your back or a Ford 9 on your work bench?
 

·
Registered
1967 400/400
Joined
·
2,115 Posts
Discussion Starter · #15 ·
True. Checking the float level on an Edelbrock is best done before you ever install it on the car since it needs to come off to do it anyway. You need to remove the top of the carb to do it, not something I'd risk doing on the car for fear of dropping something small into the engine. That being said, it takes about 5 minutes to do and you only need a drill bit (I can't recall the exact size right now) to use as a gauge. Like a lot of guys on here, I don't race mine so I'm not concerned about squeezing every last horse out of the stable. I use what is easiest for me since I am not a master tuner by any stretch of the imagination.

I'll add that this is a good thread Army started. These carbs don't get any love at all on here and, for years, I thought I was the only one on here running one.
Popping the top on an Eddy carb is very easy to do on the car. Just have a magnetic pick for the little clips! I think its about 8 screws, the banjo bolt, and 2 clips. ALWAYS remove the air cleaner stud too, or you could snag the gasket.
 

·
Registered
1967 Lemans 1967 GTO parts car
Joined
·
589 Posts
Motor vehicle Green Blue Gas Engineering
I have a Carter, Rochester, Autolite and 10 Holleys (most non functional). I buy a car and there will be a Holley in the pile of parts somewhere. The Edelbrock/Carter type carbs the width surprised me. It gives you more room front and aft. I think it is interesting the different approaches to getting the job done.


Good Write up army, I agree with the adjustments on it because it is not that easy with the Q-Jet . A company called I5 in California makes a good Q-Jet for around $ 380
I might have to look into that. Would be nice to have a quadrajet again.
 

·
Premium Member
Joined
·
539 Posts
They do sound like nice carbs and look better than Rochester's, they would look real good on a dual quad set up and don't need to be turned sideways like Holleys 👍
These are older Edelbrocks but they fit fine and run well on the old P65 dual quad intake. I believe the outer dimensions are similar for the newer Edelbrock carburetors.
 

Attachments

·
Registered
Joined
·
110 Posts
I agree with you Army. My son and I love to tinker with the cars. This year we have tested and tried about six different carbs just cause we can. When I bought my Tempest, it had a 500 Edelbrock on the 326. It ran well. When I bought my barracuda, it had a 600 Edlebrock on the 273. For kicks we swapped the carbs to see if they would be a better match but didn’t notice much difference power wise. Although on the Barracuda if I really keep my foot down it seems to run out of fuel so I’ll deal with that as I get time. Maybe toss the 600 back on.

Anyway, we had a brand new 750 Edelbrock we tired running on the 326. That defiantly woke that engine up. We messed with that one for about a week and runs very well except for a flat spot off the line we need to fool with. Currently we are messing with a Qjet that been doing well but, I want to revisit the 750 once we are done playing with the Qjet.
Jim
 
1 - 20 of 52 Posts
Top