a tale of two carburators

i have a 3310 holley 750 on my vette. it has a mechanical choke. i just bought a used 390 holley to use on my '72 datsun 240Z. it has an electric choke. so the question is, can i just swap the mechanical choke on the 750 to the 390 and the electric choke from the 390 to the 750? then, if i can, is hooking up the electric choke as simple as wiring 12v through a NC temperture switch?

The Holley choke parts will interchange between Holley carbs, so swapping parts around is no problem.

However, a correctly jetted Holley seldom really needs a choke, and the choke tends to cause more problems from an over-rich condition than solving cold-start problems. If you don't mind "feathering" the throttle for the first 2 minutes of cold operation, I'd recommend removing the choke altogether.

If you use the electric choke, you don't wire it through any temperature switch - you wire it to an "IGN" source on your fusebox. As an alternative, you can run a wire from the choke to your windshield wiper motor - the wiper motor is "hot" any time the ignition is on. Whatever you do, just don't connect the choke to the positive terminal on your ignition coil.

Lars

o.k. so far i've found what you say to be true. although the 750 has a mechanical choke, i haven't had to use it yet. like you say, i feather the throttle for the first minute or two of drive time and it seems to work just fine.
now, what i (apparently) don't understand is how the electric choke operates. if i understand you correctly, you're saying it takes 12v any time the ignition is on? if that's the case, what determines when it opens and closes? i was under the impression we only sent 12v to it when it was cold (water temp under 100* or so) but you're saying this isn't the case. if only for the sake of me learning something new (and sounding totally like a n00b) could you elaborate on how it works?
thanks.

The choke closes without voltage. If you only sent voltage to the choke when the engine was cold, the choke would open when cold, and close as soon as you cut the voltage to it after warm-up... That, obviously, would never work.

Voltage is applied to the choke at all times when the engine is running. The choke starts out closed when the engine is cold. As the choke heats up from the applied voiltage, it opens up at about the same rate as the engine warms up. To keep the choke open on the hot engine, voltage must be applied continuously when the engine is running.

aaaahhhhh! makes much more sense. now that makes life easy! :drink:

I don't know where you are and the weather but i had an 81 Chevy Silverado with a 350/190hp and the choke started sticking. I would have all kinds of black smoke and it ran like s**t in the morning. I farted around with it changing the choke and i don't even remember all the stuff i tried.
I live in the LA area so it never gets that cold so the choke wasn't even necessary. I disconnected it altogether and drove it for 20 plus years going to very cold areas hunting Wyoming, Montana. Colorado every year and even the snowy mountains of Big Bear California and all i'd have to do is feather the gas pedal a bit and it always ran like a champ. I loved that truck almost as much as my Vette but not the 8 mi. per gal. i shall miss her allot, she had 170,000 miles and still ran like a new truck.
Mike