Which ECM do you have, a 1228747? I'm guessing you have either a 2500HD+ or a 7.4L? You can just swap the 700R4 in but, if you want the TCC to lock up, you'll need a 1227747 ECM or even an EBL Flash-II and the wiring harness for the 700R4.My 89 has a TH 400 (wierd) and I would like to swap in a 700R4. Has anyone done this?
Your '89 must be a 2500/3500...yes, that swap is possible, but if you do any kind of heavy work, I'd leave the more robust transmission in there.My 89 has a TH 400 (wierd) and I would like to swap in a 700R4. Has anyone done this? Thanks.