[Skippy597]

Hey guys,
I'm sure some are getting tired of my posts but I'm still trying to figure out the direction I want to go with my build.

So what do you guys think Tri-power versus dual quads? What performs better? What drives better? What's cooler to see under the hood? And what intakes and carbs should be ran for both? Edelbrock P22, offenhuaser 360, 180?

I asked about the holley carbs on the Tri-power page and got a hard no regarding them lol.

I personally love the look of both but for some reason I don't see a lot of GTOs (or any pontiacs) running dual quads so I think that makes it pretty cool.

Thanks,
Ryan Paulson

[tom s]

Offy better than a E intake.One less carb to deal with.If setup progressive driving on a 2 bbl with either.Have driven tripowers and dual quads since 1962 and prefer 2-4s.2 of my 3 pontiacs are 2-4s now and hope the 3rd one in the near future.Both great eye candy.Tom

[slowbird]

Originally Posted by tom s

Offy better than a E intake.One less carb to deal with.If setup progressive driving on a 2 bbl with either.Have driven tripowers and dual quads since 1962 and prefer 2-4s.2 of my 3 pontiacs are 2-4s now and hope the 3rd one in the near future.Both great eye candy.Tom

Tom on the 2-4 and progressive linkage, your running on the 2 barrel (primary side) on both carbs correct?

[tom s]

No,only the front of the rear carb.Tom

[slowbird]

Originally Posted by tom s

No,only the front of the rear carb.Tom

Interesting, do the other 6 barrels open together then or is fromt carb progressive also so it goes 2 barrel to a 4 barrel then all 8? Clearly i have zero experience with 2-4 in a street setup lol

Loads of experience with tri-powers and love them! Very unique sound at full throttle from my experience and can preform great when setup correctly

[tom s]

2 bbl and then the rear pics up the front and you end up with all 8 at full throttle.If racing I went solid on both.The factory 2-4 421 SDs came with progressive.Tom

[Charlie Brengun]

My car (68 GTO) came with an offy dual quad and two holley 0-9776 450 cfm carbs without progressive throttle linkage. I have not done any tuning to it yet but it runs pig rich the way it currently sits.

[steve25]

Charlie, that Pig richness is going to ware out your rings and cylinder walls dam fast!
Ask me how I know this , lol!

That Carb ( one Carb) wants to see full Manifold vacuum to both idle right and transition into the power circuit right, let say 15"Hg for the sake of discustion, and now your splitting that in two by running 2 Carbs!

Each Carb in a way now thinks that due to the low vacuum condition that the throttle is near halfway open all the time!

[carbking]

I run dual quads with solid linkage on my shop truck, and have for almost 25 years. Both carbs run simultaneously. Both have idle circuits, both have manual chokes.

Runs great, and delivers exceptional fuel economy (on the highway, not so exceptional around town, but still not awful, better than it did with a single 4-barrel).

Jon.

[carbking]

Got called away before I could finish my answer.

Totally agree with Tom that the Offy is superior to the e.

Carbs become a matter of choice; however, you will find genuine Carter AFB's DESIGNED FOR PONTIAC will require less modification than anything else. Fairly close behind the Pontiac AFB's would be Buick AFB's. And then would come Chrysler AFB's. Depending on your skill and time available, how many parts you have, and especially how much money you don't mind spending for additional parts; other carbs can be made to function.

As far as performance, I have yet to see a tripower that would come close to a good set of dual quads on the same car!

The tripower is eye candy. The dual quads are also eye candy, that works much better as well.

But this is the "street" section, not the race section. A single 4-barrel, a tripower, or dual quads are capable of getting you an expense-paid vacation to the do-right hotel in any state in the union; so maybe it just comes down to what YOU like the best.

For racing, 50 years ago, it was dual quads hands down. But dual quad manifold design has not kept up with single quad manifold design, and for all out performance, a single quad is probably the ticket. The racing division of Pontiac proved in the early 1960's that while tripower sold to the masses, it was not competitive in racing. So the Super Duty cars used single quads, and dual quads.

Jon.

[tom s]

The thing with my most recent 2-4 install I used a converted repop SD Bathtub tub intake I’m trying to get in production.I have driven one with a flat floor plenium for more than 20 years and is a great street driving intake.The newer version has a W shaped plenum and drives equally well.Put a 100 or so miles on it last weekend from 1500 too about 2200 RPMs and it low RPM throttle response on a single 2 bbl is amazing.Tom

[Skippy597]

When referring to the offy intake are you talking about the 5499? Isn't that a single plane design? Doesn't that hurt some low end driveability. Also did offy make a dual plane dual quad intake?

[b-man]

Tri-Power fan here. Easy to set up, it’s a factory option so everything is readily available either OEM or aftermarket.

A must under the hood of a ‘64-‘66 GTO.

Not into the dual quads unless it’s built using 421 SD pieces or a fairly accurate representation of that.

[carbking]

Originally Posted by Skippy597

When referring to the offy intake are you talking about the 5499? Isn't that a single plane design? Doesn't that hurt some low end driveability. Also did offy make a dual plane dual quad intake?

Skippy - Offenhauser made several different aftermarket manifolds for Pontiac, as did other companies. This list might help:

https://www.thecarburetorshop.com/Po...emanifolds.htm

Jon.

[Mike Davis]

Keep in mind, there were 2 different height versions of the 5499.
I have one now that is about 1" taller than the other version I had both had a 5499 part number.

[geeteeohguy]

I run the born-with tripower on my '65 GTO that has been there for56 years. Rebuilt it once about 35 years ago. Works flawlessly. Also have a '66 unit I have run on various cars, including my '67 GTO. The trips feel like a 50 HP gain over the Q-jet on that car, easily. There is no comparison. The tripower carbs also seem to hold onto todays crappy fuel better. It evaporates easier out of the small, low float bowl of the Q jet. My '61 Corvette runs the factory dual quad set up with an aluminum Winters intake and dual WCFB Carters. That car can sit for 3 weeks and it fires right up. The system works very well on a 383 stroker I have in the car with progressive factory linkage. Finally, a friend built up a 462 in the early '80's off of a '70 455HO that we put in a '66 GTO with an M-22 and 4.56 gears. Car ran an Offy dual quad intake and twin AFB's. We were getting on the freeway one day on the on-ramp and he nailed it in first or second gear and snapped the wheel studs on the rear wheels. Aircraft studs after that. Raced it a few times, even against a blown 454 Chevelle, and cleaned up. That car was brutal.

[PontiacJim1959]

Originally Posted by Skippy597

Hey guys,
I'm sure some are getting tired of my posts but I'm still trying to figure out the direction I want to go with my build.

So what do you guys think Tri-power versus dual quads? What performs better? What drives better? What's cooler to see under the hood? And what intakes and carbs should be ran for both? Edelbrock P22, offenhuaser 360, 180?

I asked about the holley carbs on the Tri-power page and got a hard no regarding them lol.

I personally love the look of both but for some reason I don't see a lot of GTOs (or any pontiacs) running dual quads so I think that makes it pretty cool.

Thanks,
Ryan Paulson

I prefer dual quads, but the tri-power is an icon symbol for the GTO, but I prefer to see them on the correct and availble years. A tri-power on a 1968 GTO or later looks odd and out of place in my book. Dual quads on any year looks great.

As stated, with dual quads, you want progressive linkage, not straight linkage where both carbs are run together. You run on the primaries off of 1 carb, then when you kick it, the secondaries open as well as activating the linkage which opens up the second carb.

For carbs on dual quads, the AFB is the way to go. Check out the Edelbrock AVS2 in the 600 CFM rating. I feel these are better than the typical AFB with the annular ring and adjustable secondary air flap like a Q-jet.

Never had dual quads on a Pontiac, but did a Chevy with a dual plane intake and pair of Lincoln 462 CI AFB's. I did have them hooked together. Screwed in the idle mixture screws on one carb and ran off the other - factory duals used 1 carb without the idle circuit (?). Had a big cam. Gas mileage was about 8-10 MPG's depending on how I ran it, but mostly horrible as I could watch the gas gauge needle drop quickly on a Friday night cruise. It also ran rich as I never made any jet changes , so I had a good ignition system and ran the JC Whitney muti-ground strap plugs that didn't foul out like standard plugs would. Ran like a raped ape and would put you back into the seat.

A friend had a '66 GTO with the Offy 360 dual quads - it ran well.

Key is using a good pair of air cleaners that enhance the dual quad look. I like velocity stacks, but there are other choices.

Did have dual 4's on my '57 Pontiac, but only ran off of 1 carb and had a block-off plate under the other one. Nobody was the wiser. They were head turners.

[Paul E]

I AM NOT A CAM EXPERT!
But it is almost as important when changing manifolds that you have the correct lobe separation for the vacuum characteristics of the intake manifold runners. Just changing from a single to a dual or Tri could be a problem depending on the cam and cause tuning and drivability issues that could be impossible to fine tune. This is often missed in many discussions. I believe most manufactures had a different cam when they went from a single to dual cam in a similar engine build.
Paul

[Skippy597]

So the more I research it and look into it I think I want to go with a edelbrock p65 intake and dual Carter afbs. I just think the look will be more unique, and since I'm not trying to do a gto clone I think the Tri-power is not needed but still want something cooler than a single.

I do know that performance wise a good single on am edelbrock rpm performer is probably the way to go but it's just kinda boring.

What is the reasoning on people preferring the offy? It seems like everywhere but on this forum the edelbrock is preferred. I just like the idea of a dual plane setup more.

[carbking]

The e intake is preferred by the Chevy folks on Chevy engines.

The e intake for Pontiac has Chevy spacing rather than Pontiac spacing.

Pricing may have something to do with the e preference.

But it is your build, your choice.

Jon.