Carb selection help for new engine

[Burn 14]

Hi All,

 

I'm in the process of buying a carb and need some help. I think I've narrowed it down to a Holley 770 Street Avenger, Holley 650 double pumper or a Holley 3310 750 vac secondary. My budget is in the $350 range.

 

I'm not sure if I'm way off on my selection or not. My motor is a 351W, heads are World Windsor Sr, camshaft is a Lunati mechanical (Advertised Duration (Int/Exh): 277/284; Gross Valve Lift (Int/Exh): .562/.565; LSA: 110), Edelbrock RPM intake. I'll be running a 4-speed toploader and 3.70 locker rear end gears. Operating range will be from idle to 6500 RPMs.

 

The car will be 95% street and 5% track. I want to be able to tune the carb since the cam is on the large side. I also want a snappy throttle response.

 

Any help would be appreciated.

 

Thanks. Jim

[Burn 14]

Hi All,

 

I'm in the process of buying a carb and need some help. I think I've narrowed it down to a Holley 770 Street Avenger, Holley 650 double pumper or a Holley 3310 750 vac secondary. My budget is in the $350 range.

 

I'm not sure if I'm way off on my selection or not. My motor is a 351W, heads are World Windsor Sr, camshaft is a Lunati mechanical (Advertised Duration (Int/Exh): 277/284; Gross Valve Lift (Int/Exh): .562/.565; LSA: 110), Edelbrock RPM intake. I'll be running a 4-speed toploader and 3.70 locker rear end gears. Operating range will be from idle to 6500 RPMs.

 

The car will be 95% street and 5% track. I want to be able to tune the carb since the cam is on the large side. I also want a snappy throttle response.

 

Any help would be appreciated.

 

Thanks. Jim

[Burn 14]

Hi All,

 

I'm in the process of buying a carb and need some help. I think I've narrowed it down to a Holley 770 Street Avenger, Holley 650 double pumper or a Holley 3310 750 vac secondary. My budget is in the $350 range.

 

I'm not sure if I'm way off on my selection or not. My motor is a 351W, heads are World Windsor Sr, camshaft is a Lunati mechanical (Advertised Duration (Int/Exh): 277/284; Gross Valve Lift (Int/Exh): .562/.565; LSA: 110), Edelbrock RPM intake. I'll be running a 4-speed toploader and 3.70 locker rear end gears. Operating range will be from idle to 6500 RPMs.

 

The car will be 95% street and 5% track. I want to be able to tune the carb since the cam is on the large side. I also want a snappy throttle response.

 

Any help would be appreciated.

 

Thanks. Jim

[6T9Mach1 12]

I think that you are really looking at a Holley 750 DP for that combo. Honestly, I would look for a used Barry Grant Mighty Demon 750 w/ annular boosters. This would be the best fit IMO and it will be within your budget.

 

I know someone is going to post something about carb cfm calculators...throw them in the trash. A carb is only too big when it cant provided an adequate signal to the boosters anymore. With a dual plane intake manifold and annular booster you will have plenty of signal.

[6T9Mach1 12]

I think that you are really looking at a Holley 750 DP for that combo. Honestly, I would look for a used Barry Grant Mighty Demon 750 w/ annular boosters. This would be the best fit IMO and it will be within your budget.

 

I know someone is going to post something about carb cfm calculators...throw them in the trash. A carb is only too big when it cant provided an adequate signal to the boosters anymore. With a dual plane intake manifold and annular booster you will have plenty of signal.

[6T9Mach1 12]

I think that you are really looking at a Holley 750 DP for that combo. Honestly, I would look for a used Barry Grant Mighty Demon 750 w/ annular boosters. This would be the best fit IMO and it will be within your budget.

 

I know someone is going to post something about carb cfm calculators...throw them in the trash. A carb is only too big when it cant provided an adequate signal to the boosters anymore. With a dual plane intake manifold and annular booster you will have plenty of signal.

[maxum96 32]

Of the carbs you listed, I'd use the 650 double pumper with your combo. As mentioned by 6T9Mach1, you might even benefit more from a 750 dp.

[maxum96 32]

Of the carbs you listed, I'd use the 650 double pumper with your combo. As mentioned by 6T9Mach1, you might even benefit more from a 750 dp.

[maxum96 32]

Of the carbs you listed, I'd use the 650 double pumper with your combo. As mentioned by 6T9Mach1, you might even benefit more from a 750 dp.

[69gmachine 15]

Given that it's going to be 95% for the street, go with vacuum secondaries. The Holley 3310 is tried and true, you can't go wrong there. I'm using a re-issue Ford 735 cfm Holley 3310 only because it has annular boosters. Annular boosters will give great throttle response and mileage that's as close to FI as a carb can get.

 

Two other options for a stock stroke 351W that have annular boosters and vacuum secondaries are the new Summit Racing carbs (they have a 750 cfm for $280) and a 600 CFM Autolite 4100. The Autolite may sound a bit small, but it will easily support 400HP. I'd bet that with a good 3/8" fuel line and modified inlet it would go over 450.

Edited March 10, 2010 by 69gmachine
more info

[69gmachine 15]

Given that it's going to be 95% for the street, go with vacuum secondaries. The Holley 3310 is tried and true, you can't go wrong there. I'm using a re-issue Ford 735 cfm Holley 3310 only because it has annular boosters. Annular boosters will give great throttle response and mileage that's as close to FI as a carb can get.

 

Two other options for a stock stroke 351W that have annular boosters and vacuum secondaries are the new Summit Racing carbs (they have a 750 cfm for $280) and a 600 CFM Autolite 4100. The Autolite may sound a bit small, but it will easily support 400HP. I'd bet that with a good 3/8" fuel line and modified inlet it would go over 450.

Edited March 10, 2010 by 69gmachine
more info

[69gmachine 15]

Given that it's going to be 95% for the street, go with vacuum secondaries. The Holley 3310 is tried and true, you can't go wrong there. I'm using a re-issue Ford 735 cfm Holley 3310 only because it has annular boosters. Annular boosters will give great throttle response and mileage that's as close to FI as a carb can get.

 

Two other options for a stock stroke 351W that have annular boosters and vacuum secondaries are the new Summit Racing carbs (they have a 750 cfm for $280) and a 600 CFM Autolite 4100. The Autolite may sound a bit small, but it will easily support 400HP. I'd bet that with a good 3/8" fuel line and modified inlet it would go over 450.

Edited March 10, 2010 by 69gmachine
more info

[Burn 14]

Thanks for the comments, guys.

 

There's a Barry Grant Demon 750 on eBay right now going for $310. I'll see how much it ends up going for.

 

The Summit racing carb looks like you get a lot for your money. I wonder how good the reviews are.

Summit website says they carry both vac secondaries and mechanical secondaries models and only the mech. sec has annular boosters.

 

Would the summit mechanical be a good carb or should I stick with a Holley or BG? Decisions...Decisions....

[Burn 14]

Thanks for the comments, guys.

 

There's a Barry Grant Demon 750 on eBay right now going for $310. I'll see how much it ends up going for.

 

The Summit racing carb looks like you get a lot for your money. I wonder how good the reviews are.

Summit website says they carry both vac secondaries and mechanical secondaries models and only the mech. sec has annular boosters.

 

Would the summit mechanical be a good carb or should I stick with a Holley or BG? Decisions...Decisions....

[Burn 14]

Thanks for the comments, guys.

 

There's a Barry Grant Demon 750 on eBay right now going for $310. I'll see how much it ends up going for.

 

The Summit racing carb looks like you get a lot for your money. I wonder how good the reviews are.

Summit website says they carry both vac secondaries and mechanical secondaries models and only the mech. sec has annular boosters.

 

Would the summit mechanical be a good carb or should I stick with a Holley or BG? Decisions...Decisions....

[6T9Mach1 12]

The Summit carbs are an old Holley design carb that Summit bought the rights to. Holley makes the carbs for Summit. They are good carbs from what I hear. A Holley double pumper will be very similar. A BG Mighty Demon is a better carb. Are you looking at a Speed Demon or a Mighty Demon? Make sure its a Mighty Demon you are looking at and has annular boosters; they make them with both annular and down leg.

[6T9Mach1 12]

The Summit carbs are an old Holley design carb that Summit bought the rights to. Holley makes the carbs for Summit. They are good carbs from what I hear. A Holley double pumper will be very similar. A BG Mighty Demon is a better carb. Are you looking at a Speed Demon or a Mighty Demon? Make sure its a Mighty Demon you are looking at and has annular boosters; they make them with both annular and down leg.

[6T9Mach1 12]

The Summit carbs are an old Holley design carb that Summit bought the rights to. Holley makes the carbs for Summit. They are good carbs from what I hear. A Holley double pumper will be very similar. A BG Mighty Demon is a better carb. Are you looking at a Speed Demon or a Mighty Demon? Make sure its a Mighty Demon you are looking at and has annular boosters; they make them with both annular and down leg.

[brianrupp78 10]

So whats better about a holley double pumper vs the summit mechanical secondaries(double pumper)? I was thinking about getting a summit carb to save some cash. Would I see a lot of drop off? And could someone tell me more about annular boosters?

[brianrupp78 10]

So whats better about a holley double pumper vs the summit mechanical secondaries(double pumper)? I was thinking about getting a summit carb to save some cash. Would I see a lot of drop off? And could someone tell me more about annular boosters?

[brianrupp78 10]

So whats better about a holley double pumper vs the summit mechanical secondaries(double pumper)? I was thinking about getting a summit carb to save some cash. Would I see a lot of drop off? And could someone tell me more about annular boosters?

[maxum96 32]

Given that it's going to be 95% for the street, go with vacuum secondaries.

 

 

Don't know if you missed it, but the OP is running a 4 speed with 3.70 gears and a healthy cam. His best bet for performance most likely will be a mechanical secondary carb vs. a vacuum secondary carb. His motor will wind up quicker than a car with a automatic transmission, small cam, and low rear gear ratio. Hence the benefit in his case of a double pumper over a vacuum secondary.

[maxum96 32]

Given that it's going to be 95% for the street, go with vacuum secondaries.

 

 

Don't know if you missed it, but the OP is running a 4 speed with 3.70 gears and a healthy cam. His best bet for performance most likely will be a mechanical secondary carb vs. a vacuum secondary carb. His motor will wind up quicker than a car with a automatic transmission, small cam, and low rear gear ratio. Hence the benefit in his case of a double pumper over a vacuum secondary.

[maxum96 32]

Given that it's going to be 95% for the street, go with vacuum secondaries.

 

 

Don't know if you missed it, but the OP is running a 4 speed with 3.70 gears and a healthy cam. His best bet for performance most likely will be a mechanical secondary carb vs. a vacuum secondary carb. His motor will wind up quicker than a car with a automatic transmission, small cam, and low rear gear ratio. Hence the benefit in his case of a double pumper over a vacuum secondary.

[6T9Mach1 12]

Don't know if you missed it, but the OP is running a 4 speed with 3.70 gears and a healthy cam. His best bet for performance most likely will be a mechanical secondary carb vs. a vacuum secondary carb.

 

Agreed.