Should I install a Performer Intake and 4 barrel carb on my stock 307?

[splehigh]

Presently my stock 307 with 2 barrel carb is leaking a small amount of oil at two of the intake bolts. The motor was totally rebuilt about 10,000 miles ago and runs really well other than the choke needing some adjustment.

Since I have a brand new Edelbrock Performer intake laying here, should I install it while I'm at it along with a 4 barrel carb?

If so, what size carb should I use? Would it be possible to gain some mpgs if my primaries were smaller than the stock 2 barrel jets? I'm thinking maybe 500-650 range?

Opinions would be appreciated. Thanks!

[huero]

650 is too big.

[splehigh]

What size do you think would be best?

[oldgold70c10]

If your tracking oil leaks, you may want to check your valve covers first. I've had many leak before and make it look like the intake leaks oil.

[R.L.]

500 cfm should be fine, yes go ahead and make the install.

[Dan in Pasadena]

Look for some Craigslist headers while you're at it. Not nearly as much gained if you improve the intake without improving the exhaust.

[Irishpilot]

Intake and exhaust is great, but if you're heads are stock, with the stock ports, you won't be taking advantage of the benefits.

[cparman]

My 69 307 2bbl was converted to a Performer manifold 600 Holley w/electric choke HEI dizzy. setting up for a 200r4 tranny, and that truck ran PERFECT!! I am not a fan of headers on this setup as the are a waste of money IMO.

[prostreetC-10]

^^^ couldn't disagree more. I think headers and intake are the cheapest improvements initially you can make to ANY motor. If your truck ran great.....it would have ran better!!

[BlackTopMotors]

A combo would be nice (since it is stock and had a 2 barrel I wouldn't go too big on the carb...add a basic dress up kit (if you don't already have that covered) ...have an organized detailed engine compartment... your good to go!

I prefer headers...

From Edelbrock Site:

http://www.edelbrock.com/automotive_...erformer.shtml

EDELBROCK PERFORMER SERIES 600 CFM, ELECTRIC CHOKE CARBURETORS
CALIBRATED FOR FUEL ECONOMY
Designed for small-block and small displacement big-block engines, these carbs are recommended only for stock to Performer level applications. They are not recommended for use on RPM or Torker II intake manifolds. Match with an Edelbrock Performer or Performer EPS manifold and other brands of similar design. Calibrated 2% leaner than #1405. Includes both timed and full vacuum ports for ignition advance. Comes with: Metering Jets - Primary .098, Secondary .095; Metering Rods - .075 x .047; Step-Up Spring - yellow (4" Hg). Use our Carb Stud Kits #8008 or #8024 if needed, see Installation Items. For auto trans throttle lever adapters and more, see Tuning Accessories.

http://www.edelbrock.com/automotive_...s_shorty.shtml

[Hubscrub]

Originally Posted by cparman

My 69 307 2bbl was converted to a Performer manifold 600 Holley w/electric choke HEI dizzy. setting up for a 200r4 tranny, and that truck ran PERFECT!! I am not a fan of headers on this setup as the are a waste of money IMO.

thats a nice looking setup, and yes i don't see why not install it if you already have it but i too am no a fan of headers i have never liked them my .02

[QKENUF4U]

geezzz the boosters as big as the engine in that pic...

[prostreetC-10]

lol.....I had a 68 GMC custom camper or camper special (can't remember what it was called) but it had a factory 396 with power brakes that would move the hair from the back of your head to the front if you mashed on them.....that setup almost touched the radiator!!! It seemed huge.

[1-PU70]

I ran that intake on my 307 for years. I think a 500 is to big. I ran a Holley 390 in mine. Check Holley's web site, they have a carb calculator. Good luck.

[turp mcspray]

Originally Posted by prostreetc-10

^^^ couldn't disagree more. I think headers and intake are the cheapest improvements initially you can make to any motor. If your truck ran great.....it would have ran better!!

x2!!!!

[cdowns]

oil leaks on intake bolts is common when installed without a premium thread sealer like the manual says

[68 TT]

I had a 69 Camaro with a 307 in it just like yours. Swapped out the small stock cam for a little bigger one out of a 300 hp 350 and put on a Performer & 600 Holley to replace the 2-barrel carb. That thing was a blast. It made a huge difference. Most people who rode with me couldn't believe it was a 307 in there.

The car already had headers on it when I bought it.

The small valve heads on the 307 may not flow as well as a set of 1.94's but it can still wake up the engine quite a bit to swap out the cam, intake & carb to maximize the engines potential.

Just putting the larger carb on there without swapping out the cam for something bigger probably isn't worth it. You are half way there when you have the intake off so why not got the rest of the way and put the cam in there too.

[68lwb292]

Just for info, I'm running a 450 Holley on a 82 1.8 Toyota Corolla. Sure it has a header and cam but its a 4cyl! If you do cam and headers you would need at least a 650. Find a Holley Economaster for your stock motor you might be surprised. I've used them on small motors before with surprising results.

[prostreetC-10]

I wouldn't say you are exactly 1/2 way. You need a balancer puller/installer. Will need a new timing chain and on and on. I do hear what you are saying though TT. I think a lot would depend on his level of ability. Much easier to mess up a cam install than an intake. Then you almost get into the "why do it to a 307 when a 350 will give you such a better return on your effort. Them 307 heads are small too! I think the intake is a .75 and the exhaust is a .5. LOL

What you really need to do is be prepared that these gains will be quite small in the "seat of your pants dyno"!!!!

[cdowns]

i ran those 390holleys on my stockish 2.3 pinto engines but were too small when i hotroded the engines and i needed to stepup to a 500 after that it ran alot better

['72customdeluxe]

I would use the manifold because you have it, but a stock quadrajet manifold would probably build more torque. I would run a quadrajet or
390 holley

[ChevyLvr4Life]

I have a 307 w/ 2bbl in my 70 C10. Couldn't never seem to get the 2bbl to run right even after rebuilding it. I put a Holley 600 I had on it using a 2 to 4bbl adapter. That size carb seems to do really good on there. My engine is stock. I also have an Edelbrock performer intake lying around that I've
thought about putting on there someday, right now it runs good so I'm not gonna mess with it.

[prostreetC-10]

BTW....a 600 isn't too big of a carb if it's an 1850 style. It's a very forgiving carb. Simple math:

A 4412 500 cfm 2 bbl has a 1 3/8th venturi with a 1 11/16th throttle bore. It's exactly 1/2 of a 750 double pumper (except for a 50cc primary pump).

A 600 cfm has a 1 1/4 venturi with a 1 9/16th throttle bore....much smaller than the 500 and used through the vast majority of the driving/engine needsd. This is why people put on 4 barrels over to barrels to increase gas mileage.

The 500 also has a down leg booster which creates a quicker signal than the slower 600's straight leg design. The 2 barrel has to be bigger initially to supply the needs in the upper rpms. Not to mention the 500 has a 50cc pump and the 600 has a 30cc one. This is also why vacuum secondaries are always at least recommended for the street. They are basically 2 barrels until you need more!!

Any questions class?

[LONGHAIR]

Comparing 2 barrel carburetors to 4 barrel models is not a "fair" or "equal" thing. The CFM ratings are based upon different levels of vacuum.

If you placed a 500CFM 2 barrel onto a flow bench and them followed it with a 500CFM 4 barrel, w/o changing anything, the results would surprise you

[prostreetC-10]

Not to meantion the fact that many carbs don't even flow their advertised cfm rating. The very cool Holley 950 HP comes in at a little over 800 cfms.