Cool! Thanks for the info...I'll check on all of the above.

 

every carb calculator i have seen has said that at 80% effeciency a 390cfm is the right size for a 289
http://www.4secondsflat.com/Carb_CFM_Calculator.html
when i went from a holley 600 to the holley 390 all the hesitation went away.

since i am doing a cam and headers now i may upgrade to the 570 but later on.

 

I have a 289 mild cam, header, stock heads and manifold. I run a 600 Edelbrock and it works great.

[IMG]local://upfiles/32123/93ECDF55931B4B43B8DF19676B4A9F46.jpg[/IMG]

[IMG]local://upfiles/32123/F8ACED564224491AB25250BC5054481A.jpg[/IMG]

[IMG]local://upfiles/32123/79CE8BEDEBF84674913AEB876A58F00E.jpg[/IMG]

 

Get rid of the holley boat anchor and get a performer manifold and carb. You will not be dissapointed.

 

I'm running a 570cfm carb on my 302 with heads, intake, cam, internals and all the other bolt ons. You're better off using a slightly smaller carb if it gives you better atomisation.

 

Over the winter I switched my 65 with astock 2100 to a dual plane summit performer manifold look alikeand a 600 Edelbrock and all I can say is wow. The new set up really woke up the 289. It's a blast to drive. absolutely no problems here.

 

Boy, this thread really goes both ways.

I bought a 600 cfm 1405 Edelbrock today. Still unopened and in the box. Really tempted to switch to 500 after reading this, but I just dont know.

302, headers, dual exhaust, edelbrock performer intake, 4 sp. I want to have 275 hp- 300 hp in the end.

Just dont know.

 

Most 600's can be tuned to work on a mostly stock 289/302, but the reality is that a smaller carb will work better. The key is to have the correct carb for the correct application. Not just carb size, but the type of boosters used(which influences the size carb you can run). And most dual plane setups are forgiving of overcarburetion.

 

As 67mustang302 said above, the Performer is a pretty forgiving design. You may have to tweak the 600..but if you have the receipt and can downsize without much hassle it might be easier in the long run.

I had a 600 Holley and almost exactly the same set up on my '68 and it worked well, so the 600 should be OK if it's a pain to go back to the parts store, especially since your above stock on a lot of other power building items (headers, intake, dual exhaust). Themanual tranny also helps since you can "tweak" your take off a little by learning what RPMs you need to come off the line well. You can take off based on when you "feel" the power band kick in, as opposed to a torque converter that engages at a "set" RPM whether it's in the power band or not.

 

Sometimes if you plan on more upgrades later, you may find it worth it to just deal with getting a large carb to work now and have it for later when you need it.

Definately run a dual plane though, ESPECIALLY with an oversized carb.