I have an edelbrock that came off a 302 that I was thinking might fit my 300. I currently have a clifford water heated manifold, holley 500 2 bl and FI exhaust manifolds.
Any body tried the 600 cfm on a 300 and how did it go?

Ron

 

Should work fine. The 500 is a very popular choice, and the 600 is not that much different, according to edelbrock's published carb specs.

 

The only diff. between the 5-600 is the boosters. The bore, venturi are the same. Having said that, I do believe it is too much carb for your engine, especially if you do not have some head mods. I would try to drop the primary jet size down, and the metering rods. You can get the calibration kit for about $50 from Summit Racing. It is worth gold with these carbs.

However, I do think you would be better off just selling it on ebay and buying a 500.

 

yep - I would agree - going to need the calibration kit. Don't think I can move forward even with the 500 without one.
Everything I have read so far says no matter what carb you put on there is tweaking time required. So far I have spent many hours (and much money) on the Holley 500 and its still not quite right. Close but still needs some tweaking. I decided it was close enough.
So I am expecting to spend many hours on the edelbrock also!!
If the bore and venturi are the same then I would plan on changing to the 500's metering rods and jets and work from there.

Thanks!
Ron

 

Don't assume you'll need to change needles and jets. Edelbrocks are very forgiving out of the box. 500, 600 cfm both work no worries on a 300; I've run both on mine. If you have to tune it, use the rod/jet chart for the 600 instead of trying to retrofit it into a 500.

For starters just get a set of step-up springs and try the softest, lowest vacuum setting. Then try the next stiffest, and the next until part throttle acceleration smooths out. Play with the accelerator pump setting. It may be fine as is.

 

Thanks BaronVonAutomatic - I will try that.

 

You were 100% right BaronVonAutomatc - the 600 is working like a charm.
Put the edelbrock on tuesday and what a difference! So far no off idle bog at all and accelleration feels stronger. And all I have done so far is adjust the air/fuel mixture!!
I have only run the holley 500 2bbl and the 450 4bbl and both required a lot of work to get the off idle bog out. Never did get the 450 to work right.
Have not run wot on the freeway yet so may need to work on the secondaries but from what I can do on the side roads maybe not.
The primary butterflys are a touch sticky off idle so I need to double check the gasket/adapter fit. Going to run it for a while just to be sure its not from sitting. I only feel the stick when blipping the throttle under the hood - not with the gas pedal but it needs looking at.

Thanks for all the help!
Ron

 

Far out, glad to help. Since it feels okay as is you can play with the step-up springs and accelerator pump to maybe squeeze a few more mpg out of the truck.

You might check the linkage on the carb side for the sticking. One of mine had the primary shaft linkage binding on the secondary shaft linkage and holding the primaries open a bit. It caught a little and I couldn't get the idle down until I bent the secondary linkage a wee bit.

 

Thanks!
Going to be working on the electric choke today and will check the linkage. Does sound like whats happening since it won't idle below 900 even with the idle screw not engaged.

 

I meant to say check the linkage on the choke side rather than carb side, fwiw.

 

Thanks
I will look at that next weekend - with the way I have the carb on the manifold that means taking it off to really check out the choke linkage. Planning on that anyway to double check gaskets and put a smidgen of sealer on them now that everything is adjusted, my fuel line has been properly re-routed and the throttle linkage is solid again.