'88 1-Ton Crew Dually to SRW & T-400 to 4L80E Conversion

[Evil Trailblazer SS]

Originally Posted by Jonboy

You can get a harness from www.fuelinjectionconnection.com for $245 that is new and set up to run the 4L60/80E. If you are running TBI already it should be a no brainer. Get an ECM that was from a TBI/4L60/80E truck, and it should be plug and play. Robert can probably set you up with that, too.

I would think you can use your existing column; I am using the original one in my '74 to shift a 700R4, and it grabs all of the gears. The quadrant is in the cluster, and is held in place with 2 screws, once you get the cluster out.

I used teh FIC harness in my swap, and I thought it was a quality piece. I am very pleasd. They should be somewhat local to you, Adam. They are in Golden.

Thank you for the link! I just spoke with Robert and my transmission builder, it looks like this is going to be a very simple project to complete!

1. New Engine/Transmission Harness for '94-'95 TBI/'93+ 4L80E will be a direct plug in setup! ($305.00)

2. 16196395/16197427 PCM purchased from Robert at www.fuelinjectionconnection will include all programming for the 454 TBI/4L80E and the E-Prom chip for the truck! ($140.00)

3. All I need is a DRAC module to compute the 40 pulses for the VSS (Vehicle Speed Sensor) signal. I can use either an adjustable unit from www.jagsthatrun.com or he can supply one for my specific tire size/gear ratio ($110.00) or I can get one local, which I will probably do since we know and have worked with the owners of Nevada Speedometer.

The only things you need to worry about are as follows:

1. The internal transmission harness of the transmission
- The pre-'94 units had the old style harness plug with a bolt to secure the external harness to the transmission's internal harness, you I have to make sure the trans is built with the newer style harness.

2. When you select your transmission, you need to be careful with the older trucks. You need to make sure your transmission has BOTH the Input Speed Sensor AND the Output Speed Sensor. The newer TBI trucks with the 241 t-case had the Output Speed Sensor on the tailshaft of the t-case, so you need to convert the transmission to include the sensor on the side. (All 4L80E cases had provisions for both sensors, but the later trucks did not include the sensor) and you will have to make sure the transmission gets built with the reluctor wheel installed into the trans.