PE to LA2 computer

[8svo6]

I Picked up an LA2 computer from a jy today. I bought it just in case my PE went out. I have an 86 SVO, and I want to make sure I can use this LA2 for a back for one day I may need it. From what I understand there are 4 pins that need to be swapped. I've checked everywhere possible and thats what they're saying about LA3 computer. Now assuming that LA3s and LA2s aren't much different from each other, what pins exactly do I swap. If possible please show diagrams. Thank you.