Anyone Using 500CFM After-Market Carb?

[colnago]

I currently have an Edelbrock 1405 4BBL carb, rated at 600CFM, which some say is too big for my 352. I started looking on Google, and found that the Eddy 1405 and 1406 carbs are quite popular on anything between 300 and 450 CI. So, that got me wondering if anyone is using a smaller after-market carb. Anyone? Does anyone have any practical experience, good or bad, in comparing the two sizes?

Joseph

[SoCal250]

I have the Holly 500 cfm performance carb shiny looks killer although I only been able to break in my cam so far I was having fuel pump issues so I'm converting to a elec fuel pump, I had it idling briefly then my pump took a dump . It's a2bbl number 4412s there's tons of you tube videos on it and some have this 2bbl modified on cars with 500/600 HP removal of the choke plate accelerator pump mods etc it will be just as good as 4bbl only no secondaries I'm just going to put my kickdown a little sooner to compensate for no secondaries . I'm running a 1" alum carb spacer with it , stock was 300 cfm I also have a rebuilt 350 cfm number 7448 it's also considered a performance carb it has a 30 cc accelerator pump the 500 has a 50 cc Im not ashamed to say I run a 2bbl carb matched with a 265 comp dual energy cam ....

[WarEagle]

Check out this link to determine proper CFM for an engine:

https://www.summitracing.com/expertadvi ... calculator

If you want to run a bigger 4 bbl carb, you may want to jet it down, run it lean and get it with vacuum secondaries that won't open unless the engine needs it.

[colnago]

I guess that's why I was asking about other people's experiences. If I use the basic carb formula, I get about 400CFM. That means that we're all over-carbureted for standard street use (not all of us; just the majority with after-market carbs).

I just ran into someone on eBay who has machined some adapters to turn a 600CFM Edelbrock into a 500CFM Edelbrock. I'd still have to rejet, but it's an interesting (and relatively inexpensive) concept.

Joseph

[WarEagle]

Yeah, a new Holley 390 cfm carb runs around $500 for some reason. a 600 cfm is $200. Sounds like BullSmack to me.