night rider Veteran Member. Yes the 1996-02 L31 350 vortec heads will bolt to ANY gen 1 350 engine.

The ’96-’00 350ci Vortec 5700 engines enjoy lots of aftermarket support to help improve the 255 hp and 330 lb-ft of torque they’re rated for at the crank. An engine swap can be quite costly, so putting even a quarter of those funds into your Vortec 350 engine could get you where you want to be.

You can install the 383 with Vortec heads on it. The HT383 that was available from GM uses Vortec L31 heads, the GMPP 383 shortblock and the Ramjet 350 roller cam with specs of 196°/206° duration at 0.050″ lift and 0.431″/0.451″ of lift on a 109° LSA produces 340 [email protected] and 435 lb/ft of torque at 4000rpm.

The best-known and most-beloved has to be the “350” or 5.7-liter version; especially with Chevrolet and GMC trucks. They are powerful, tough, reliable and it is relatively easy to “soup up” or increase their performance.

The regular 350 head uses a 90 degree bolt angle while the Vortec uses a 72 degree bolt angle. When the head is bolted to the engine, all the attachment bolts point straight up, as experienced mechanics know.

You can use a carb intake for vortec heads, just get an intake made for vortec heads. A regular chevy distributor will drop right in. Chances are you’ll need to run an electric fuel pump since your block is likely not drilled for a fuel pump pushrod.

Another important result of carb sizing to remember is that smaller CFM carbs will generally give better throttle response in low and mid range rpm, while bigger CFM carbs will develop more power at high rpm. This is because the smaller CFM carb will keep the airflow velocity higher at lower rpms.

A 600-cfm carburetor may perform quite well on a stock 350 Chevy. However, the minute you start weaving in power adders like a hotter cam, a dual-plane performance intake manifold, and aluminum heads you’re going to need 700-750 cfm.

450-470 hp

Yes, they will give you more horsepower. But carb spacers have another important function. They also act as insulators which keep engine heat away from your carburetor to ensure cooler incoming air and fuel.

500hp

10 Best Carburetor For 350 Chevy Reviews & Buying Guide

1. Edelbrock 1406 Performer – Best Overall Carburetor For 350 Chevy.
2. New Carburetor for Type Rochester 2GC – Best Affordable Carburetor for Chevy 350.
3. Holley 0-1850S Model – Best Value for money Carburetor for Chevy 350.

If the carburetor is “too big” then the engine will not be able to keep enough air flow through the barrels for fuel delivery to occur. Which would explain why the engine would work at highway speeds but struggles at low rpms.

650 cfm

750 cfm

Most ‘universal performance’ 600-650 carbs are calibrated for small blocks. Some are, some aren’t. Anyway, 750cfm is fine for stock to mild 454 big blocks. They can work real well for mild to wild 454 big blocks but a step up in CFM will pay off with more power.

How to calculate Carburetor CFM. The formula for calculating how much CFM (cubic feet per minute) your engine requires is: CFM = Cubic Inches x RPM x Volumetric Efficiency ÷ 3456. Any ordinary stock engine will have a volumetric efficiency of about 80%.

CFM rating goes off engine size and max rpm. Its also dictated by intake type and whether you want to drive it on the street. From calculating with 85% VE and a single plane intake, the engine will need 855 to 1015 CFMs. So though way at the bottom, the 850 will run that engine to 9000 rpms.

600 isn’t too big for a 305. There’s not a whole lot of good to be said about Edelbrock carbs though, except that they’re cheap. With 100% VE, you’d need to spin the 305 to about 6800 RPMs to flow a total of 600 CFM.

A bigger carburetor alone will not make your bike go faster. In most cases, your bike won’t even start or idle roughly with a carburetor that’s too big. For more power, you should look into a full system performance exhaust and rejetting your carb (not replacing it entirely).

Short answer – a carb can’t give you a horsepower increase. you are under or over jetted. If you have a stock motor with a stock carb in stock trim then a carburetor can open up the horsepower that your engine is capable of making.

10-20 horsepower

With a 2 barrel carb, you get what you get. In other words; if it is a 350 cfm carb, it’s always a 350 cfm carb. This means the 600 cfm 4 barrel will actually have better throttle response, quicker off the line power and much better low-end get-up and go compared to a 350 cfm 2 barrel.

750 CFM

Significantly lower gas mileage compared to any of the Edelbrock carbs. As a whole, here are a few benefits Holley can boast about: Smoother acceleration than Edelbrock. Fares better with more in-depth tuning.

Vacuum Secondary Carbs are a good choice for street cars with automatic transmissions. Mechanical Secondary Carbs are often used in race cars that operate at wide-open throttle. They are also a good choice for lighter vehicles with a manual transmission, big cams, and lower rear end gears.

770 CFM

That combo would probably make around 465 hp and nearly 500 lb-ft, but at less rpm. But never mind that. The point here is 502 lb-ft at 4,700 rpm and 500-plus horsepower from 5,700-6,200 rpm….Hot Rod’s Proven Recipe For A Simple Chevy 383 That Knocks Down 500 HP And 500 LB-FT.

My 383 stroker runs 180-200 with a 180 stat. Hot summer days, like 95*+ in town sends the gauge to 210-220 on occasion, but a quick run at any speed brings it right back down.