Holley dp or Speed Demon???
 

For a descently built motor w/auto trans and street driven, which would give better all out performance/adjustablilty: Holley 650 double pumper or a Speed Demon 650? either way, I'm pertty sure I want to go with something that still has a manual choke for cold starts. It's for a small block with the Performer RPM cam/intake (port matched, ported/polished/milled factory heads w/perf. valve job, headers).
Any info would be appreciated.

Road Demon
 

I use the Road Demon. I like a vacuum secondary for streetability. The vac. secs. also work well with an auto trans giving less bog than the double pumper. My Road Demon is 625 cfm, just about right for my 306. The only thing bad about the carb was cheap electric choke/fast idle linkage. If you use a manual choke, that won't be a problem.

Rev

The demon carbs about supost to be top notch.

Right now I'm running an edelbrock 600 which seems a little too small for my setup and stutters sometimes. I still need to check my plugs to see how it's running, but I'm pretty sure I want to go with a 650. As far as being the right size, if a Holley 650 was good than would a Speed Demon 650 manual secondaries be about the same? Also, with the Perf. RPM dual plane intake, should I go with a 1 inch spacer (open or 4 hole????)?

Small block
 

Your original post says a "small block". Is it a 289, 302, or 351?

Rev

It's actually for my vans 355 (sorry it's a chevy), I'm trying to get it set up good so I can start to mess with my 86 GT soon. Anyway, it's set up like I have it in my profile. The carb also smells like gas when it's siting, I might try and reset the bowl.

750
 

Sorry for the confusion. I think that a 650 is a little small for a 355. I would use a 750, but still with vacuum secondaries, especially in a van with auto trans. Either the Holley avenger or the Road Demon would work well. Not sure if they can be had with manual choke or not. The Holley electric choke does work well. I had to fool around with the electric choke on my Road Demon a fair amount. The only criticism I have with the Demon.

Rev

I definitely need to get something, my car wouldn't stay idling today, it was running real rich and and stuttering when it did run. I'l probably mess wiht the float tomorrow, but I'll probably end up going wiht a 650 speed demon. Are there any parts like jets, etc. That aren't interchangable w/holley parts?