Almost stock 289 idle?

I have a 64 1/2 mustang with a 289. It has been bored out 60 over. The cam is stock. The only performance upgrades i have done to it are the 4 Barrel edelbrock carb( 500 cfm electric choke and manual secondaries), long tube headers, and after tomorrow a limmited slip 8" with 3.55. My question is on todays gas, what should the idle be around?

I don't think "todays gas" has anything to do with idle speed....It's largely a personal preference thing..Don't have it too fast to where it may run on when you shut it off and not too slow so it stalls easily when put in gear..I would guess somewhere around 700 rpm give or take a little.

I fully agree. 700 is a good # for a stock cam in your engine.

I checked up in my manual for a 67 289 and it said about 550 rpm. Try that at the minimum but no more than 750 rpm at most for idle.

Idle in park when cold is like 1100, hot it is like 800. Idle in gear while cold is like 800. Idle in gear while hot is like 600. If your idle in park is more then 400 rpms then something probably isnt right. vacuum leak or something

I have a 289 in a 1966 mustang. The engine is has a Edelbrock 500 on a cast iron factory manifold, Edelbrock Performer Plus Cam, Dual exhaust 2/14. Now I have owned this car since 1980 when leaded gas was still available as well 94 octane at Chevron. The car ran and idled much better with the leaded fuel. The cam and intake combo was about the same as it is now. My car idles at 850 in park and 600 + in drive. The old setting of 6 degrees BTDC and trying to get the car to idle smooth is hard to accomplish, at least for me. I did have the car at factory settings in the 80's with leaded high octane gas. I have my distributor recurved which now gives me the advantage of setting my initial timing at 16 degrees BTDC. The engine that I rebuilt with a Crane Blueprint Series Cam with factory specs didn't idle as good as it did when I bought the car, so I went a step more and put the Edelbrock cam in , not a bad idle.

All the Best

Greg

On a stock (nearly) 289 you should be able to idle at 550 in neutral with a manual tranny but if you have a C4 you will need to have it idle at 550-600 in drive.