Intake/Carb combo on 461ci
 

Hi everyone,

First post here so I hope I'm in the right place. I'm sure there have been similar questions answered but there are a dozen different rabbit holes to go down so I'm throwing this out to the hive mind.

I had a 461 built for my 79 about 18 years ago from a 1973 400. Due to life it has sat for the better part of a decade and I never really had the time to sort everything out. I'm finally in a place where I have the time and money and want to do it right.

The setup on the car right now is an old Holley (I think a 650) with a mechanical choke sitting on an Edelbrock performer intake. I'd like to go back to an electric choke and the Holley needs work so I'm weighing my options.

I still have the stock 1973 intake (PN: 494282) and a Q-Jet (PN: 17059272) that was on the 301 that was in the T/A. My research seems to tell me this carb should be an 800 cfm and could be a pretty solid setup for a street car.

Now to the question at hand. What setup would you guys recommend? Should I rebuild the Rochester and swap back to the cast intake, buy an electric choke Holley for the Edelbrock, or maybe something different?

The car is a weekend cruiser but is the only "fun" car I have left so I may take it to a track day here or there.



Digging way back to some receipts I found the car has:
461 stroker with eagle rotating assembly and SRP forged pistons
Lightly worked Pontiac cast #46 heads
Comp Cams 51-232-3 (.454 lift, 268 duration)
TH350
2.73:1 rear gears

Thanks everyone,
Dan

The standard response from most folks around here including myself is the factory intake with a freshly rebuilt Quadrajet. Hard to beat the combo on the street and track as long as it’s not a max effort build.

17059272 is a good core to start with and responds well to the mods laid out in Cliffs book.
Because it was intended for a 301, the secondary airvalve needs it stop ground down to provide the air valve to open farther (1.270?)to keep it from choking off your 461.
Also the 17059272 had a small hole cross drilled in the secondary fuel discharge nozzles.
These should be swapped out with solid ones.
A punch/round rod that fits snuggly inside a tweaked/wiggled will take them out easily.
Replace with solid and a dab of red loctite.
Only tap them back in far enough so yo dont block the verticle fuel passage.

Another tid bit of Quadrajet tech to be aware of is worn out primary throttle shaft bores in the base plate.
Most know of the drill/rebush with bronze bushings, but there is another way without drilling throttle plate.
Quadrajets have a factory counter bore that just happens to be .030 larger that the throttle shafts. And is bery rairly ever warn to enough to impede on these counter bores.
What I did was to get a sheet of .015 Teflon sheet from McMaster Carr.
I cut 2 pieces about 1" long and 1/2" wide and work them into the counterbores on re assembly.
Works real well and when a rareish carb is being used, it could save these parts from a miss drilled oversized bushing hole.

A good working 650 cfm carb will make as much power as your lightly reworked heads will allow, and especially with a Stubstack on its top side.

Either manifold will work well for your needs, but only the Performer will allow easy use of the Holley.

That Q-jet from a 301 will need more then just a fleshing up to work well on your CID motor.

Those 2.73 rear gears will limit your fun when and if you do make it to the track.

Agree with Pav that your 9272 QJet is an excellent unit for a performance build.

If it were me, I’d try to find a ‘72 OEM intake, and save a little weight over the ‘73 unit.

It’s easy to convert the Qjet to electric choke.

Get your parts from Cliff…he carries 44 single taper primary rods that will allow you to dial in your AFR with ease. Plus his custom metric mixture screws will allow MUCH better access than the stockers.

X2 on parts from Cliff!!!
He can set you up with all parts you need. When you buy his parts he is also able to help with answers to questions that the good buddies on Ebay can't answer when they sell you carb parts.

What kind of HP are you making? I have a 67 Firebird with a 72 400 that was taken up to a 461 using worked Edelbrock heads and is pushing about 560hp. It also has a 5 speed and 3.73s. My builder used a QUICK FUEL 850 BRAWLER with Edelbrock Victor intake but that was too much intake and after talking to Butler I switched it out with a Performer RPM. It runs a lot better on the streets now. I'm also running Doug's headers and a flowmaster exhaust.

jwcfbd are you still using the850 Brawler?

I originally was going to use a Q Jet on my 469 with an Edelbrock RPM with Cliffs parts but after swapping an 850 Holley it picked up almost 80 horsepower. I would not have believed it if I had not seen it on the dyno. The only downside of the Holley is the factory air cleaner needs to be clearanced for the adjusters for the float bowl. It runs fantastic and glad my buddy suggested trying it while we had it on the dyno. It made 580 hp and 590 torque.

Wow, that’s a substantial gain that I wouldn’t have expected, with that much of a hp gain I’d run a Holley too!

The first E head motor in my 78 TA I ran an HO intake and the Qjet-done by Brad Urban's Carb Shop until I found an extra Shaker base to use a Demon/Holley after "massaging". Swapped an out of the box Demon 850 at the track WITH the adapter and picked up 0.3 seconds! Later added the T2 and picked up even more. The rear bowl adjusting area we had to graft in a section from a cheap drop base.

Great information for the board and to give access to the write up. Here is the link: http://rmcavoy.freeshell.org/Q_Jet_bushings.html

yes I am but I am toying with the idea of a Sniper 2 with timing control.

This is the way, the only reason IMO to convert to a Sniper type system is for timing control, otherwise you’re better off with a carb.

Out of interest Cliff sent me one of his modified Q-jets to try when I had my 462cid street combo installed. Back-to-back test, same timing and shift points for both.
With my HP950 Holley it ran 11.54 at 116.73 mph and with his Q-jet it ran 11.64 at 115.59 mph. Only made two runs with the Q-jet so nothing conclusive but I thought it ran quite well.
The intake was a Performer RPM and no air cleaner installed.


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Wow! I've been swamped with work this week and haven't had time to check the forum. Thank you to everyone that replied. I'm planning to reach out to Cliff this week to see what he can put together for me for the Q-jet.

The car has never been on a dyno. I've had it since I was a teen and when I started making adult money I had a friend of a friend with a machine shop do the engine work. He is a great machinist but terrible at finish work so I kind of ended up with a basket case.

How do you like the Doug's headers? I've got a bad leak on one of my manifold gaskets so i'm planning to buy some new headers but want to be able to justify if the price is worth it over a set of ceramic coated long tubes from summit.

No matter what headers you buy/use get a set of Remflex gaskets, best out there and help seal any minor imperfections in the cylinder head.

FWIW. I have used these on a couple sets of headers and they work great.