600 or 750 Holley
Drifting
Joined: Jan 2002
Posts: 1,484
Likes: 0
From: Northampton Ma
Re: 600 or 750 Holley (mrvette)
I bought the Holley Street Avenger 670 cfm, it's recommended for 300-400hp applications. I talked to the guy at Jegs and he recommened the Holley over the more expensive Speed Demon. You should also spend the extra $150 and get an Edelbrock intake manifold.
Thread Starter
Drifting
Joined: Mar 2001
Posts: 1,896
Likes: 0
Re: 600 or 750 Holley (mrvette)
Were running a Holley Dominator (1100 cfm) on a SuperCharged 502 in a Baja 26FT boat. No problems what so ever. we have been for a year or so. I guess who ever has been working on Holley's around you just don't do somethign right...
no offense or anything.
no offense or anything.
Burning Brakes
Joined: Oct 2000
Posts: 936
Likes: 0
From: Chicago Illinois
Re: 600 or 750 Holley (Ryan77)
Jegs doesn't recommend Demons because they stopped carrying them. Barry Grant would not take the returns, so Jegs was getting stuck with them. If you look on their site now they are selling a remanufactured Speed Demon vacuum secondaries 750 for $287. That's a great deal on a real nice carb.
I would highly recommend for the original poster that he goes out and finds a used 650 cfm 4150 double pumper dual feed Holley at a swap meet, or on ebay, it should cost somewhere between $25-100+ depending the condition and how lucky the buyer is. If it needs a rebuild, then all the better, that way you can learn how the carb works and that knowledge will make it much easier to tune it. A rebuild kit is cheap, between $15-35, and it's very easy to do. Just takes some time and elbow grease and you can really make an old carb shine (and work great too). Then you can take that extra money and get a new intake.
When I was building my 388 (~450 hp), I had trouble deciding between a 650 & a 750. A 750 will give more top end power but at the loss of some bottom end. I did end up going with a 750 and I was happy with it. If the motor was making closer to 400 hp I would definately have run a 650. I'll be running a 750 on my 550 hp 434 until I go EFI. Keep in mind that on a street car it's torque that accelerates, not peak horse power. Gaining 15 foot lbs at 5500 isn't worth losing 10 ft/lbs at 3000 and losing throttle response, a little gas mileage, IMO.
Rob
I would highly recommend for the original poster that he goes out and finds a used 650 cfm 4150 double pumper dual feed Holley at a swap meet, or on ebay, it should cost somewhere between $25-100+ depending the condition and how lucky the buyer is. If it needs a rebuild, then all the better, that way you can learn how the carb works and that knowledge will make it much easier to tune it. A rebuild kit is cheap, between $15-35, and it's very easy to do. Just takes some time and elbow grease and you can really make an old carb shine (and work great too). Then you can take that extra money and get a new intake.
When I was building my 388 (~450 hp), I had trouble deciding between a 650 & a 750. A 750 will give more top end power but at the loss of some bottom end. I did end up going with a 750 and I was happy with it. If the motor was making closer to 400 hp I would definately have run a 650. I'll be running a 750 on my 550 hp 434 until I go EFI. Keep in mind that on a street car it's torque that accelerates, not peak horse power. Gaining 15 foot lbs at 5500 isn't worth losing 10 ft/lbs at 3000 and losing throttle response, a little gas mileage, IMO.
Rob
