ninety4three4

iTrader: (13)

i am going to be going with either a TH350/400 behind my 93 LT1 block and ECU in my 76 and i was wondering whether to use a A4 or M6 engine harness as my M6 harness is kinda cut up, does their need to be some kind of speed sensor for the ECU to function or do you just eliminate that all together. Im assuming that you would use the M6 harness however the 93's were still vacum controlled 700r4's so im not sure what they used for speed sensors, any input would be greatly appreciated, thanx!

LT1

iTrader: (1)

My 69 Firebird has the TH350 in it. It shift's using vacuum source. Use a vacuum source from the intake run it to the modulator on the trans and should be it.

ninety4three4

iTrader: (13)

thats not really the question, im using a manual valve body so i dont need a vacum source i was asking if i should use an M6 or A4 ECU harness since their are no sensors on the TH400's there is no need for the A4 connectors basically what do you guys do with your harnesse when you put a TH350/400 in your ltx 4th gen cars cars in order to have the ECU function properly

LT1

iTrader: (1)

If im not mistaken, you dont really need speed sensor input, unless your running ABS or using the LT1 Cluster/speedometer.

You could run either the A4 ECM / harness or the M6 ECM / harness.

jasonisdn

iTrader: (1)

speed sensor: 8655315 GM
reluctor: 8655291 GM
harness to speed sensor: 12085498 GM
the reluctor part number has changed and is 1 dollar more now. go to gmpartsdirect and copy the prices. then go to a local delaership and see if they will match the price. i did it today for my swap. by the way i am using a 6 speed harness and leaving the 6 speed program in it. you will need to tie off the switch under the clutch also. i might be leaving something out, if i am someone will chime in.

ninety4three4

iTrader: (13)

this is going into a 4th gen im assuming so you are trying to retain all of the factory functions, that is not of concern to me as my 76 dosent have abs obviously i figured i could just remove the pins for the speed sensor from the connector but if the ECU needs to see the clutch position sensor in the closed position to allow the engine to start i dont know what ide do their short of splicing the the wires together maybe thanx so far for the input but im still in need of some more help

jasonisdn

iTrader: (1)

oh i was thinking you were using all the outputs from the ecm not just the motor sensors and controllers. on the question in the first post, you don't need the vss hooked up.

the_merv

iTrader: (88)

You could probably run the Factory stuff for that year to the Speedo without a problem. The Speed Sensor goes into the PCM with the Auto Cars for the Shift Tables and the Out-put Signal to the Gauges. With the Manual Cars then it just is for the Gauges and the Reverse Lockout. It also sends a Signal to the Cruise Control Module for both a Manual or Auto Car. If there is something else that is does, I've never heard of it.