On my recent buy, (1970 442 convert.) I learned the hard way about passing gear. I assumed kicking the pedal down would shift the tranny into passing (2nd) gear like all the others. Out for a drive and tried it. Broke the throttle cable!! Looking at the service manual, found that the TH400 has a kickdown switch wired to the tranny. Looked under the dash, no switch/ bracket or wire. Is this a simple fix? SInce the car has an after market Holley, would this be simple fix? Any tips? thnx

 

The kickdown switch should be attached to the gas pedal. There are a few universal switches you can adapt at the carb.

 

If the car doesn't have the switch, it was either an MT car originally or it's not a real 442. The switch looks like this. Repros are available. The wiring should be in place under the dash.

 

Thanks for the info. . As I understand the passing gear, TH350 have cable to the carb. TH400 uses the switch at the pedal that connects to the tranny. No cable to the carb. Is this right?

 

The TH400 was electric only. An electric solenoid on the valve body in the trans routes the trans fluid in a way that activates the kickdown valve.
The TH350 used a cable, but on Oldsmobiles is didn't go to the carb, it went to the accelerator pedal through the firewall. You can see that in the top center figure of the diagram I posted above. Note that there are two cables running to the accelerator on TH350 cars.