I had good luck with changing the 7.4L $0E to 5.7L and running in a conversion. I've had good luck tuning several of these PCM in $0D, $0E and even the $85. But after looking through the 4.3L Manual bin and comparing it to a 5.7L $0D bin I'm not so sure? There's just a lot of things differant, so do you go with minimum and tune or maximum and tune? Theres a lot differant!