We just realized we need a kickdown switch for our 68. Keep in mind, we bought a shell without motor or transmission and we're missing lot's of parts and we've never built a car before. We put a 1976 400 w/TH400 in it. We are starting to wire the car and realize the kickdown switch should mount to the carb. Our's is a holly 650 attached to a an edelbrock performer intake. Also, we are using a 67 throttle assembly which uses a rod vs. the cable.
Our question is, what kind of switch/setup can we use to make a functional kickdown? We understand the original kickdown is quite expensive and since our car is not a 1000 point restoration, could we set up a different more economical way? We've seen a few options that mount to the gas pedal, but we do not want to go that route. We want soemthing on the carb... any ideas? Anyone done this before?
Thank you

Both Lokar and B&M offer aftermarket kickdown set-ups that work with the TH 400. I will probably go the Lokar route myself as that system places the switch out of the way down at the transmission.

The Lokar setup also will work with your non-OEM Holly carb as it is cable operated.

When I had an ST300 without a kickdown switch, I made one for uner $10.00 and it worked well.

I bought a microswitch from an electronics store and soldered two leads to the normally open positions on the switch. One lead went to the black wire with yellow stripe providing power to the windshield washer. The other lead went to the downshift solenoid on the side of the tranny.



I used a piece of scrap aluminum to make a bracket to hold the switch with the left rear carburetor hold down bolt on my Quadrajet. I positioned the switch so that it was open until the throttle was floored.



When the throttle was wide open, the switch was thrown by the mechanical part of the secondary linkage on the left side of the quadrajet.

I used a break switch on mine. I think I got the idea from someone hear. Since I had a stock q-jet I got a reproduction bracket from chicago muscle car.

The problem with these type of switches is the kick down is supposed to be set somewhere near 'wide open throttle' and not right at 'wide open throttle'. You will need a switch that is activated and then allows some further travel after activation for it to work as the factory one does. There aren't many switches made like this. That's why I designed a pedal style set-up that uses a readily available(affordable) switch that was designed for this application. Some of the aftermarket switches incorporate a 'cable and spring' to recreate the 'further travel' that the original switches had.

That is some good info. I did not know that.

I installed the Lokar brand. Works well and is easy to set up. Make sure you get the mounting bracket for it as well.

My under $10.00 switch could be fired before WOT by bending the tab so that the throttle linkage hit it sooner. I knew I would get rid of the ST300 so an expensive solution was not what I was looking for.

Thanks for all the responses and options!

Hoody, does the lokar attach to the tras. on the drivers or pass. side? I ask becuse our neutral saftey is attached on the drivers side to the trans pan. I dont know that we have any room left. We're using a 69 slpstick shifter with a 68 handle (so it looks correct). The 69 slapstick didnt have the NSF attached to the shifter like the 68 did, so we bought american autowire NSF and it attaches as mentioned above.

The switch is housed in a metal box that bolts to the driver's side of the tranny. It uses two of the existing pan bolts and mounts on the top side of the tranny. I believe it is located right next to the shifter cable bracket.

i used the B&M switch. Works perfectly...

I've found some of these one other brands of cars over the years in the junk yards. I also found a lot of the idle stops from other brands that work if you use the correct bracket. And, the voltage is the same. Just saying this because most the Pontiac switches I have found will work, but the plunger is plastic and is either cracked or part of it is missing.