I'm having no luck finding a 65 4bbl intake for my "66 so I'm going to look at getting a performance 2bbl carb. At first I was told to get a holley 2bll 500. Then I was told that would be too much Carb and I should go with a 350 car. Is anyone running a performance 2bbl on a 300 engine here? Looking for suggestions. My car is stock. Thanks.
those 2 holleys ( most common are 4412 = 500 cfm , 7448 = 350 cfm ) offer alot of options n upgrades since they are basically front half of a 4bbl . 350 should be fine for a stockish 300 cruiser . with a few basic mod's to engine 500 should be fine . either way you can adjust your choices for jetting , power valve , pump shot , etc easily . also consider the rochester 2bbl . if i remember correctly there are a couple cfm choices - 300 range and a 435 i think . and there are mod's you can do to those . there's a nice rochester 2bbl info thing on here also .very good .
Thanks for the info. I found a used 4412. What engine mods would I need in order to put one in my car? I was told to consider getting a Rochester off a later modle car. But I will look into a Rochester. Just looking for an upgrade over my current stock carb.
If you have a good 2.25 or 2.50 inch dual exhaust system with low restriction mufflers , good tune with electronic conversion , rebuild the 4412 to stock Holley spec , carb adapter and try 'er out . Later , cam etc , rear gears , trans upgrade . Do your homework , ask questions .
bolting on a holley won't net you much of anything. if the rest is stock the factory carb is your best choice. I'm sure you would see some gains with a quality rebuild and a good tune.
When you're using factory street gearing and the factory stall converter, a good running 2 barrel engine will give you many smiles per gallon, and will surprise a lot of people. Been there, done that. You're not going to beat all-out racing cars, and the track will mislead you. Getting a car to run good at the track will give you a car that is good for running at the track. Much of a car's performance exists in the way you drive it, not just the car itself. There's more to performance than straight-line holeshot perfectly timed racing using heavily modified suspensions. A couple cars I used to own, a 1970 Plymouth Satellite and a 1968 Buick Skylark, both of which had 2 barrel engines, did very well when performance demand was below 4500 RPM. The Plymouth was the one that surprised me the most. It had a 318-2 and would ping on any fuel less than premium (the Buick did this too). It ran almost as well as the Buick, and was a larger car with a smaller engine. I won't go into too many details here, other than both cars would effortlessly spin the tires on dry pavement. With a reverse-drive shift from a rolling reverse burn, the transmission on both cars would shift into 2nd gear before the car started to roll forward, then continue to burn rubber in 2nd gear for a pretty good ways. This is not the sort of behavior I would necessarily recommend, just sharing some past events to indicate the cars' power. I can tell you though, that the Mopar 904 transmission will NOT hold up to much abuse, unlike the GM super turbine/turbo hydromatic transmissions, which will take an incredible amount of abuse. Anyway... My recipe is simple: compression is key to power when you don't/can't rely on scavenging/VE to pull in more air/fuel for better cylinder compression. Focus your power where the rest of the drivetrain is happiest. You can put in more gears and a 4.10 rear end and rev the hell out of it, or you can leave the factory stuff in there and focus on producing your power further down in the RPMs, which 2 barrels will do, and will give excellent performance from 1500-4500 RPM for engines ranging in the 300-350 CID range. Don't think that a huge dual exhaust is what you need, as would be true for a higher revving (or larger displacement), better breathing engine. You'll want a larger than factory single exhaust for the most performance with a 2 barrel engine using manifolds, and the merge pipe is possibly the most important aspect of this design. Get rid of the "T" connection that comes from the factory, as this is incredibly inefficient for gas flow, and get yourself a nice "Y" design, with the entrance tubes as close to parallel as you can, and as close together as you can, which will then lead into a much larger single pipe. This can then either lead back out to a press bent dual exhaust which shares the flow burden on more restrictive dual mufflers, or keep the exhaust big and single back to a good flowing single muffler. For reference, a single 2.5" mandrel bent system will flow about as well as a press bent 2" dual system, so use those sizes in conjunction with the recipe described above. Get a 2 barrel that will flow, since the head and intake runner design on the Buick engine provides excellent velocity and fuel atomization retention, so a larger carb is recommended. This means a big 2 barrel for this combination. There are adapter plates for mating a Holley to a Rochester intake if that's the path you choose. Either path is viable. Rochester 2gs were made in 2 bases: the 'small base' and the 'large base'. Yours is the small base. My records indicate 2 CFM sizes for the small base and 4 CFM sizes for the large base, and the sizes depended on the application, with the large base carbs showing up in the late 60's and early 70's depending on the model and application. CFM ratings were nominal and conservative, with similarly sized Holley carbs 'showing' more CFM, the Rochesters actually flowed the same when similar throttle blades and venturi were compared. (example: the '435' Rochester large base compares to the Holley '500') Modified 2 barrels on high-revving, small CID engines will produce in excess of 500 hp (an engine dyno session on Youtube shows one such example producing 520 hp), so don't think they can't perform. This engine was built for circle track racing where there is a 2 barrel limitation rule. Für your purposes, you'll need nothing more than a typical factory assembly that's larger than what you have now, which will give you more air and fuel delivery in the RPM range you wish to operate in. Give it a good tune with a nice hot spark, and you're good to go. Don't knock it 'til you try it.
That big Rochester 2g certainly does. At least on a Buick 350, not sure how 50 less cubes will make it sound.
For some extra spring in your step, changing out the rear end for a mid-high 3 series gearing and the 200-4r transmission will be a big change over that ST300 and factory gearing. Don't let my long-winded posts deter you. Any car's performance will be improved by better gearing in both the rear end and the transmission, particularly when it's a low CID stocker. Even though I'm partial to the ST300, it does have its shortcomings. Less power = more gearing needed.
I had a 4412 on my 64 special 300 a looong time ago . didn't have a clue - first car . engine totally stock but it was a manual trans so that may have made a dif . ran good . actually it started running real good about half way through 2nd gear - a nod and a wink to my late brother in law who borrowed the car one afternoon and informed me of that initially . Edit : if you do decide to try the 4412 you have contact me back if you'd like correct spec parts info for that . Not a problem . Good to dbl check , never know what has been changed previously .
Thanks. Gears are the first thing I'm doing to the car next spring. I can feel the engine working hard and the rear end not able to keep up. I had a 88 Trans Am with the same issue. I'm going to look over the winter for a 200-4R. ST300 runs well but doesn't give me what I need. A lot of people have suggested to put in a bigger engine. I like the 300 and I think we some mods could be what I'm looing for which is a nice sounding car that has a bit of get up and go.
The sbb is a great little engine and with some more modern gearing in the car will be a night and day difference with how it drives. Also you can try D&D fabrication for an intake, they usually have a couple aluminum ones sitting around. I bought one from them about 10 years ago and was charged $350 so just be prepared to be sticker shocked if they have one. GL http://www.aluminumv8.com/
Tossing around ideas are always a good thing, even if they seem bad to some, might spark an idea for others. Who knows? Any mid 80's car that had any sort of semblance of performance used a mid-high 3 series rear end gear (3.42 or 3.73 usually) mated to the 200-4r trans, and made even the Buick v6's do ok as long as the car didn't weight as much as a big Cadillac. Ultimately, it's all about power:weight ratio and the torque multiplication, most of which is mechanical, and some of it hydraulic (for automatic transmissions). Then there's subjective interpretation. What may be 'fun' or 'powerful' to some, may not be to others. There's no disputing gas mileage though, and smaller engines with happier gearing will do pretty good in this department. This usually means mid 3 series gearing and the 200-4r trans. Put a measly 200 hp and 300 ft. lbs. in front of that with a 2200 lockup converter and you'd be amazed at the transformation from a ST300 (even a switch pitch) and 2.56 gearing. You could just leave your engine alone and keep the carb you have, as long as it's tuned well and runs good, your performance will come from what exists behind your engine. You'll get to keep your good gas mileage (probably even improve it) as well. Big 2 barrels do well on those engines, but are not exactly gas mileage friendly, especially if you like to crack it open on a regular basis. Seems no matter where you turn, you're always faced with a trade-off or a compromise, especially when you're limited (funds, skills, time, parts availability, etc. etc.). I could continue with stories of 2 barrel engine experiences, such as the ones I had with Ford Mustangs, Mercury Capris and 302 engines, as well as a Thunderbird I used to own with the same setup. They did pretty darned good for what they were, and you'd have swore it had a 4 barrel on it with the way they performed, all the while getting 25+ MPG. I've known guys who owned 289 Ford engines beefed up with 2 barrels sitting on top of them and those did alright too. A good friend of mine I've known since high school used to have a '71 Dodge Challenger with a beefed up 318 that had a lopey cam and aluminum 4 barrel intake with a Holley 650 on it that we used to cruise around in. Nice car and sounded good. Performed pretty good too. Went up against a stock Mercury Capri with a smooth idling 302 2 barrel and single exhaust engine and got his ass stomped so bad we were all laughing and scratching our heads. That little 302-2 was amazing. A couple of advantages a Holley has over the Rochester 2g carb are that the Holley's sit as tall as any other 4 barrel carb, while the 2g is 1" taller. This can matter when you wish to use carb spacers and hood clearance becomes an issue with the Rochester carbs. Another issue (minor) that could rear its ugly head is air cleaner availability, both the element and finding one to fit your larger Rochester, which used different air cleaner sizes for the carbs. The Holley uses typical ones found on 4 barrels that are much easier to obtain. If you could manage to score a 4 barrel intake, I'd recommend a 500 CFM or thereabouts square bore vacuum secondary for a stock-moderate Buick 300. It'll run well too. Yet another long-winded post from Gary, but hey it's entertaining at least (I hope).
I enjoy reading all these suggestions and stories. Thanks Gary for the latest response. I'm in the learning phase with my Skylark. I've had two 80's Mustangs with 302's. Great engine. With the proper set up that engine can really go. I just ordered my advanced curve kit today. I'm going to order the duel exhaust kit from summit soon. I'm going to keep the stock manifolds on as headers are way too expensive (cheapest set I found was $500.00). I'm going to get my carb rebuilt and continue to search for a 4bbl intake. Hopefully I can find one over the winter. Gears probably 3:42 will be done in the spring. Out of all the cars I've own I enjoy this one the most. Always wanted a car like this.
Gotta wonder though how a 500 holley 2bbl would perform on a stock 350 Buick with a good 9.0 compression. Ok maybe a tiny cam to go with it. dual exhaust with 2.5 duals. The intake is ported to the heads. Stick a 1 inch spacer under the carb too.
Gears/transmission is the way to go. Make sure you have a healthy engine (compression check, etc.) and it should be good to go.
