[DeTomaso] Carb question

[Christopher Kimball]

I have a 408 stroker with a Holley 750.  When I try to set the idle, I seem to have only two choices.  1) set the idle too fast (1800 rpms) so that when I turn on the air conditioner, the car won't die (it goes to about 1100 rpms with the a/c on), or 2) set the idle for 1100 without the a/c, but when I turn on the a/c it drops down to about 500 rpms and is at risk of dying when I let out the clutch.

I've tried adjusting the idle screw on the carb in minuscule increments, but no luck getting better results.

Suggestions?

Thanks,

Chris
3846