Quirky Holley and Alternator question

[kenlipo@domain.elided (Ken J Hitchcox)]

Tark,

Sorry if I confused you, it's my Holley 2210 CARB that is quirky. I guess
I worded that one poorly. Doh!  I have no experience with the Holley EFI.
 

Next subject:  I suspect that my voltage regulator is hosed up. Since I
have a spare alternator, can I switch regulators between the two? The
alternator was working fine except that occassionally it would not begin
putting out voltage until about 3000 rpms, then, it would put out LOTS of
voltage (according to the gauge and the tremendous increase in brightness
of the headlights) then slowly drop down to a slight positive reading.
Now, it doesn't put out any charge according to the gauge and the general
dullness of lights. 

Ken