Sooo_slow

Searched but couldn't find anything really because I'm sure no one actually actually had a 2 barrel.

Currently have a 327 (yeah I know...) carbed 2 barrel.
Motor runs strong, no issues with it.
Completely stock.
Motor is 70's era.

I want to know if it would be worth it to go to a 4 barrel. This will include probably a performer rpm (or comparable) manifold. And most likely a 600cfm q-jet or holley.

I know I may lose mpg's, but I can say I'm not concerned.

Would it be a notice-able difference?

Or should I just stay with the 2 barrel, because the motor is stock?


Thanks in advance.

Sooo_slow

I should also mention, it's a non computer car.

Gibbyzracing

Well I got a couple tips for you.... I have built lots of SBC...

First Idea for Daily driving
Edelbrock Performer/peformer Rpm intake
Holley/Edelbrock 600-700 Carb
double Roller timing Chain or Gear Drive
Aftermarket Cam(around 480/480 lift) rough idle but not to radical for street

Second Idea for more of weekend cruiser ect
Edlebrock Victor JR/Scorpion intake
Holley 700-750 DP
Gear Drive or Double Roller timing chain(depends on prefrence
Lunati Bracket Master II cam arounda 485/485 or so... Great for stock converter and street driving but great performance....

I have a 327 right now with
Comp Magnum 480/480 cam
Roller Rockers
194 heads
Gear drive
Scorpiion intake
750 DP holley
Headers
Dynomax exhaust
T5 5 speed
342 gears went 11.94 on street tires

mcampau

If you stay out of the gas (not likely) you could increase your mpg by swapping to a 4 barrel and yes there will be a noticeable difference.

theorio1025

the 600 cfm holley emissions legal carb works well on my motor. i get about 20 mpg highway with a 350, t5, and 3.73 gears. I don't get on the gas that much though

TylerP

FYI,there were no 327's made in the 70's. The last year a 327 was produced was 1969. Be forwarned,there were 2 journal sizes used in 327's! Just incase you ever need some bearings down there.

Quadrajets only come in 740 or 800 cfm ratings. The differance is the size of the primaries.

Oh,you'll feel a differance alright. That short stroke motor would love a manual tranny and a high winding cam

Sooo_slow

So in theory, a quadrajet may infact be too much for my stock motor?

Because from what I've read a higher 500 or lower 600 is what people have been recommending.(for a factory motor)

TylerP

You would think so but GM used them.

mcampau

Just because GM used them it does not mean that they are optimal for the engine. Just look at all the other bone headed mistakes they make concerning power output.

five7kid

iTrader: (14)

The q-jet is superior to any Edelbrock carb. You might be a little quicker with a Holley double pumper, but certainly not with a vacuum secondary carb. The beauty of the q-jet is it will get decent fuel economy (better than a 2-bbl, all else being equal), will handle more engine, and adjusts itself to what the engine needs. No other carb does all that in one package.

The "mistakes" the factory made were lack of optimization. Obviously, they laid the groundwork well, or there wouldn't be all those SBC's tearing up the pavement out there.

Having said all that, if the engine is otherwise stock, it's got some of the worst possible heads on it, for either power or economy. The cam is nothing to write home about, either. I don't see anything about exhaust - a critical factor.

Of course, I don't see this is in a 3rd gen, either. . .

Damon

This combo actually sounds like a VERY good candidate for a QJet swap. A QJet, even if tuned only "reasonably close" will blow the old 2G style 2bbl away both at part throttle and WOT everywhere in the RPM range. Better fuel economy potential, too. The secret of the QJet is in the tiny super-efficient primaries. If you can keep your foot out of it, that's all you're ever running on. Of course, the big 'ol vacuum secondaries are there when you need them (and ONLY when you need them).

TylerP

Q-jets get a bad rap cause alot of people dont know much about them. Once you figure out the metering rod and hanger specs you can really tune one. My cousin once had a super nice 55 Belair he restored. Eventually he put a 355 with a tunnel ram and 2 Q-jets! Now THATS a kick!

Sooo_slow

I'm just contemplating which method to go, as I can do a manifold and carb for like $100. But I was planning on just throwing a 350 in it, in the spring.

Maybe this will hold me over until I decide if I want to swap, or just build up this motor.

naf

iTrader: (7)

For the money and fuel economy I'll second the q-jet. You may even consider using a factory aluminum LG4 style intake. They're plentiful and cheap. The factory intake will probably NOT be the power bottleneck for your motor yet. Round these parts each will run $50 or less used, along with a rebuild kit for the carb, gaskets, etc. you'd be looking at around $150.