I'm in the process of building a 400 to replace my tired old LG4 in my 85 Z28. I understand the the ECM controls the carb, distributor advance, and torque converter lockup. The new setup will have a non computer controled carb and Vacuum Advance distibutor. It is my understanding that the ECM will no longer control lockup. Is there a kit or trick to make the trans still lockup in overdrive with the ECM disabled?

 

There are several, the one I like is TCI P/N 376600.

 

There is a detailed article in the latest issue of Chevy High Performance on lock-up converters for non-computer cars that might be helpful.

 

The artical on non-computer lock-ups in Chevy High Performace is excellent. go to the store and get yourself a copy. Hell, this months issue of CHP informed me quite a bit, there is a lot on 3rd gen tech this month.

 

In the 80s GM made trucks with lockup converters and no computers, on the firewall of these trucks you will find a switch with a vacume hose(goes to intake) and elec plug ins one to tranny(for lock up)and one from field(Power) The bone yards are full of these vehicles and the switches work good and can be had for just about nothing

 

You could take a vaccuum switch out of a non-computer vehicle, but the lockup on those vehicles was partly controlled by the valving in the transmission. You'd probably find it locking up too early.

 

Thanks for the helpful info. Gunna check into the TCI kit. Did not find it on there web site, gunna give them a call.