89 Silverado 700r4 to 4l80e swap

[Pro439]

So I’m not very upto date on the vintage before 96. So the computer for the 94 does it still use a programming prom? As in 96 they went to the 4 connector computer which I know a place that programs them and on fb there is a ad for proms. The 94 is still the tbi yes? If that’s the case why wouldn’t you be able to swap all the engine sensors over and then install the wiring harness and I would imagine that if the 89 doesn’t have the p/s connector or harness you would have to add that and whatever it is connected to. I’m changing a 7.4 over to a single plane intake so I am adding holes for the MAP and evap controller as I am using the stock computer. As far as the driveshafts go I would have them made. I don’t know that much about the front axle mounting to know if it’s just a swap but the rear would be and unless it was ordered with it the 8600 is only a 9 1/2 ring gear and not full floating. I would think you could just do an intake swap and then plug and play the computer. The 8600 gvw and up have multiple bolt holes for the cross member which isn’t that big of deal as you can use the cross member from your donor. Probably the biggest issue is going to be the harness that goes into the truck and the pinning of the connectors. I know the 96 and up have different/extra connectors and pins in the connectors for cruise, electric fans, fog lights and other accessories. Not necessarily better but the vortec engine can be swapped over to a 0411 computer that the early LS engines used that eliminates the ignition cutoff at 52/5500 and is more tunable. With out wiring diagrams for both trucks you won’t know what wires you have currently and what you need to add to use the other computer. The stand alone controller is so much money because I believe you get the software to program it. Shift points up/down converter lockup and unlock and how hard it shifts and I do recommend putting a transgo hd2 shift kit in it and unless you want hard shifts you don’t have to drill the shift plate

 

[tayto]

The only sensor that needs to be swapped over is the knock sensor. the harness can be swapped or you can unpin the transmission stuff and swap it over along with the P4 pcm connectors. they use the same pins as the earlier C3 TBI ECMs. I wouldn't waste my money on the Transgo kit, most of the stuff they have you do is not needed and there can be issues with the triple layer separator plate. if the trans is out you can dual feed properly and for free. install a sonnax LB1 boost valve but reuse your stock spring, block 3rd accumulator and increase shift hole sizes in the separator plate.