Big drop in idle when fans kick on???

[Pman1961]

Doing my final sorting of my new engine tranny swap in my SPF. I have one issue left to resolve. I have a 445w big hydraulic roller cam. Car idles great at 1100rpm start to go any lower the motor gets to sounding a little lazy. Anyhow, when the fans kick on it will slowly pull the rpm down to 750 or so which sounds as though the motor could quit and never seems to regain the 1100rpm idle when the fans kick off unless you press the accelerator some. If I bump the idle up another 50 to 100 rpm more it seems to take care of the rpm drop. I'm considering a dashpot at the carb wired so that it will activate when the fans run to bump the idle up some. Tomorrow I'm going to fine tune the carb and maybe play with the timing which it is currently set a 34degrees full advance. With the higher idle when you shut the car off especially when warm it may diesel a few seconds and makes a wheezing sound as it stops. Is this the typical nature of the larger cams or does anybody have a suggestion that does not require disassembly of the motor?