[Madd Syntst]

With my 455 broke in and running, it has a problem. It doesn't get enough gas when you really want to punch it (passing gear and being funny, not drags) I currently have a 650 Edelbrock (vac. seconds) on the same name manifold. My options are:
Salad bowl carb-750 or more
2-4 set up, using two 650's
T-Ram with same carbs.
Have mild cam, 10:1 comp, "Z" type cast iron exhaust, and turbo 400.

If any of you real motor mechanics(not a bolt on specialist like me) have opinions, I'd like to know them. Like I saw in another post, eye candy is a partial consideration, but not being a real mechanic, what will give me the least problems or the easiest to go to?

[christopher406]

It has been my experience that the best bet for all around power is a single four barrell. Tunnel Rams look good but are usually a dissapointment in the power output down low that you need on the street. Your 455, I would think could use at least a 750 or greater. If your ride is for show by I would put whatever looks the best, but for power you can't beat a single four. Is that your truck in the picture, if it is your my kind of guy for putting a 455 in it. Is it a Buick, Olds, or Pontiac?

[bullheimer]

from what i have read on sbc's at least the single 4 is the way to go for the most torque and streetable HP. i would getta 750. holley makes one that has mechanically assisted secondaries that made my chevelle haul *** . forget the model number, their alittle spendier than the straight vacs. puts you into the Demon range. that street tunnel ram/carb combo from summit (in the HRM dyno shoot out)came very very close to the balls out single demon 4bbl tho, and was in the same cost ball park. i don't have the issue but like i said in another post it was a couple of months back on the cover "carb shoot-out" i think was the story. could find at <a href="http://www.hotrod.com" target="_blank">www.hotrod.com</a>

[dmorris1200]

I would definately think you could do better with a bigger 4-barrel with that many cubes. I'm runing a Holley 670cfm Street Avenger on my little 302 small block. The street avenger (unless you're hooked on Edelbrock) is nice cause you can quick change the spring to change how early the secondaries open up. The other option already mentioned, the old double pumper, no question there you know them puppies are working.

You didn't mention which style Edelbrock manifold you're currently using.

[ August 15, 2002: Message edited by: dmorris1200 ]</p>

[Madd Syntst]

OOps, 455 Olds and Edel Performer. So, 750 is enuf?

[dmorris1200]

I would think around 750cfm would be pretty good. Just my 2cents.

[drewhelm]

I'm currently building a 455 Pontiac and will be using a vacuum secondary Holley 750. The 750 should be plenty for your application. Probably wouldn't hurt to try an 800cfm Qjet design. You could probably get an 800cfm Edelbrock and be very happy with the added air and fuel.

[drewhelm]

In addition my Holley 750 flows closer to 800cfm. I amde sure to break it in on a Chevy 350 and it was definitely too much carb for it.

[willys36@aol.com]

The 650 really should be enough carb for your engine. At least all the calculators say it is more than enough. Sounds like you coud use a little tuning! Have you tried different secondary springs? One cause of dead response on a punched throttle is the secondaries opening too fast. A poor boy way to check this is block the secondary mechanism closed (won't hurt it). If you car then accelerates better on the bottom end, you need a heavier spring to retard secondaries. If the stall is just at the instant you hit the trottle, then the engine kicks in, you may have an accelerator pump problem. Make sure the accelerator pump cam is tight against the pump arm at all times so ANY movement of the throttle squirts some gas.

Point is, since you say you only want street performance, a bigger carb will cost $$$$ and likely won't solve your problem.