Thinking if I remove the carb and dist for the original ECM setup on my '81 and replace with older units that are not ECM controlled....how did you address the tranmission lock up.....or did you just leave it where it did not activate?    Replacing carb and dist is simple, addressing the lock up.....I am unsure of so seek comments from you....some of the best in the C3 guys.

______________
Tommy

Provides control of converter lockup through vehicle speed on GM transmissions with a lockup converter. Eliminates converter lock and unlock cycling and premature unwanted converter lockup avoiding engine lugging and spark knock. Provides lockup at highway speeds for fuel economy. Can be used for converter lockup operation when converting a non-lockup equipped vehicle to a lock up style transmission and converter. Provides dash mounted control to govern converter lockup at any speed between 30 and 90 mph. LED tells whether converter is locked or unlocked.
Fits GM TH200, TH350, TH700R4, 4L60, & 200R4.   

http://www.bmracing.com/PRODUCTS/Transmission-Accessories-and-Kits/Converter-Lockup-Control-for-GM-automatic-trans-w-lockup-converter-electronic-speedometer

______________

Or....you could do it the easy way. 
All you need for LU to work is power and a ground...and a pressure switch. The trans already has all of these things, so....
The pressure switch is inside the trans, on the valve body. It is rated with a number, usually it will be a 33psi. This switch is what closes to provide the solenoid with a ground, allowing lock-up to occur and keeps lu from coming in too soon. What you would need is a switch with a 45, or 56 psi rating. This psi rating basically equates to road speed, so a 33psi switch will close at 33 mph, a 45psi switch closes at 45 mph, etc. I usually like to install the 56psi switch. That way, you don't have lock-up coming on before then, and lugging the engine down. The ECM would normally provide the ground, so you'll need to tie into, or cut into one of the three wires going into the trans connector to supply a full-time ground, and then change the pressure switch. All of this will take about an hour of time, including changing the trans fluid, since ya gotta remove the pan to change the switch. Best of all, all it'll cost ya is fluid, a pan gasket, and a $10 switch!
So what happens is this. With the trans wired with power and ground, and a 56psi switch, as soon as the vehicle hits 56(approx), the converter will go into lock-up. The trans gets it 12v power off of the "Gages" fuse, which runs thru the brake switch, so when you press on the brakes, lock-up will disengage.

This prolly sounds a LOT harder than it really is. Then again, you could decide to just eliminate the lock-up function, and not worry about it. The only way you'll ever see any REAL mpg with lock-up on a 350 is if you do a lot of highway driving....and even then, it's only good for about 1/2 mpg on a tank, if that.


______________

Joel Adams
C3VR Lifetime Member #56    
My Link


(click for Texas-sized view!)             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

For Goodness sake, why are you doing that??

______________
          



(click to see a larger image)

Just looking into my options, carb on now not doing perfect and figure if had to rebuilt it or get another might consider just removing the ECM stuff and go back to all manual, no electronic this and that.

______________
Tommy

I have an 81 and changed the carb and dist and added a MSD 6al.  I also eliminated all the pollution devices and cats.  I find that I dont even notice any change in the performance even though the converter does not lockup any more.