what demon carb for my setup?


New Member
Nov 24, 2003
New Whiteland, IN
I have many efi problems.... Because my car is primarly a toy now, I think I will like a carb. I really like the Barry Grant demon series carb. I need to know what will be best? 600? 625? vacume secondaries? double pumper?
Ported gt40 heads (extensively to 1262) are going to be going on this build, and possibly a cam. Help me out guys =)

Also, what lower intake would match up nice to that?
  • Sponsors (?)

Go With an Edelbrock Performer RPM Air Gap intake, as it's defenitly a great dual plane intake that not only perform's great at low and mid range RPM's but also perform's like a single plane at higher RPM's. Combine it with a 650cfm Vac. Secondary Speed Demon, and you'll be cooking with gas man. You could go with a mechanical secondary as well... it's really a matter of preference. Barry Grant's Vac. Secondary Speed Demon's come std. with an electric choke were as the mechanical secondary Speed Demon's come with no choke at all in case that matter's to you at all as well.
Hydraulic Rollers, even big ones, make really good vacuum. No need for a DP. I totally agree with everybody's advice. 650 speed demon vac sec's and an RPM airgap. On the highside you may make 340-360 at the flywheel. A carbed engine will make more HP than an injected motor but with less torque and a more peakey powerband.
I hate to be a "sales whore", but PM me if you are interested in a Street Demon I have that I want to get rid of. I believe it's a 625 with vacuum secondaries and an electric choke. With your set up it's plenty of carb. I had no problems running mid-11's on my 455 Olds with only a 750 Quadrajet. I nomally shifted at only 5,000 rpm's(bracket racing), but it would pull strong all the way to 6,000 with just a 750.
I've got one of those 650's for sale- $225 with the dual feed line. Used for a month. I also have the distributor that you will need, MSD billet,almost new,with the steel gear you'll need to run the late model style roller cams-$140 and I have a Victor Jr too- $150 (might be a bit much for your app). PM me if you're interested. I'm going to put them ebay one of these days....
I'd run a Weiand Stealth intake. I've seen mixed results with the RPM Air Gap and everyone I know (about 4 or 5 guys) that runs a Stealth has had real good results. Intake is good to 6800 rpm which is past the point where valve float happens with hydralic roller cams. And I think it's cheaper too.

EDIT: per summitracing.com

RPM Air-Gap $232 (RPM Range 1500-6500)
Weiand Stealth $166 (RPM Range Idle-6800)