Ford Repair: psom, problem failures, reset button

Question
I have just spent the last 2 weeks tracking down a bad psom in my 95' f250 7.3 soot machine well ford gets about $450 for a new one so i did what any broke guy would do and off to the junk yard i went $50 bucks later i was installing my new psom from a 92' f150 my question is could this create a problem for me the truck seems to shift early and the speedometer is off a little i have reset the cal on the psom from i think 973 to 778 for the 35" tires but it seems that nothing has changed for me do i need to spend the $450 at ford or is their something i can do to help this problem when i go to change the cal i ground out the one psom wire hold the reset button and the first code is a backward E then if i press the reset button one more time it gives me the cal code and i know that you can only do this 6 times any info will be great thanks!

Answer
I cannot find any differences in the two years as far as wiring or connections. If you put in a used PSOM and now you have symptoms that weren't evident before, chances are the used PSOM also has a problem. Failures of this component were actually quite common. Try another used part if you can find it, put your original back in to see if the shifting problem is different, or bite the big bullet for a new one. If it were me I would confirm this used PSOM is causing the shift concern before spending more money.

You didn't mention why you replaced it in the first place, my guess would be it stopped working or went blank.