The last thing I need to pick up is a new carb. This is for a 350, vortec heads, UD276H10 hydraulic cam,Performer RPM intake,Hooker super comps, full 2 1/2" flowmaster exhaust, th350, 25.6" tall rear tires and 3.55 posi. Onovakind67 was kind enough to run my combo thru his desk top dyno program and came up with 353hp and 370ft lb of torque at 5000 rpm. I believe my 2 best choices are a 650 vacuum sec (speed demon recommended by BG)or a holley 650dp mechanical secondaries.My car is 99% street driven for sunny day cruises etc. but I am looking for max performance and drivability if that makes sense. I can get a holley for considerably less $ than the demon but really don't have any experince with the mech secondary carb.(experience as in driving)I am not concerned with fuel economy on my choice either.I don't think I really need a choke either but am not sure whether you can have an electric choke on a 650dp. Any thoughts on this guys? I do have an edelbrock 600 now but believe in the research I have done I just might be leaving a little performance on the table using that carb. I don't have experience tuning carbs but want to learn. I never knew how to weld or do body work before last fall and with a lot of help from here I have got my ole girl to the point she is at now and am very happy with the results.I have installed the new cam and heads and hoping when I fire it up everything goes smooth(we will see)ok I will quit rambling on

Appreciate the input

Jerry

I am no holley tuning expert but I have two cars with double pumpers that run very concistent and dead on there dial ins most of the time. With that being said, if I drive these cars around the block or to the store, they foul the spark plugs. My vac. second carb did not run as concistent but did not foul plugs. I personaly would run the the vacuum seconds on the street. The Edelbrock is a simple carb and easy to learn but can be pain if any trash gets in it. As far as holding power back, if you do not run at the track with slicks, you may never notice it. If the edelbrock runs good with no problems, spend your money somewhere else.

Use a Q-jet. I put together a very simular combo. The thing runs super with a Q-jet.

I think that 650 Demon would fit that setup well. I would stay away from the mechanical secondary holley espiacially if your running an auto transmission. Stick with vacum secondaries. Also the holley 670 Street Avenger carburetor is a good choice. It's a little cheaper than a demon, but is a very good carburator. Just change out the clear view float plugs for brass ones, hehe. Good luck

I like my Holley DP. Works great on my combo, and has excellent response. I've never had any fouling problems with my setup. I did change the secondary squirter and jets slightly, based on the A/F monitor, but it worked great right out of the box.

In my opinion if you want to learn how to tune carbs then buy a double pumper, when the tune is right on these carbs they will not be outperformed. A 600 or 650 will be all you need. The double pumper will not foul the plugs if tuned correctly. Take your time and tune all circuits of the carb starting with the idle, then accelerator, then main jet and powervalve enrichment. graemlins/thumbsup.gif