engine idle speed

[Dugan]

What should my mustang idle at when it is in drive? it is a 67 coupe, with a 4 bbl 302 out of a 68. it has a holley 600 cfm 4 bbl carb, a 1 inch carb spacer and a edelbrock performer rpm intake. other than that the engine is stock (i think)although i think it may have a mild cam? this was sorta a mystery car when i got it
right now it idles at about 600 rpm is this where it should be?

thanks in advance.

 

[jcp123]

I have always gotten good results with 600 in D as well. Start there and if it idles a little rough, try stepping it up ~50rpm or so.

 

[D.Hearne]

Set it to as low as possible and not have it stall. More cam(overlap) and intake (single planes usually) require higher idle speeds.