3 pin to 4 pin throttle body

My question with all this is if you buy a remanufactured 96-2000 3 pin throttle body and you want to replace your wore out 4 pin throttle body with it, can't you just take the 3 pin off remove the mounting plate and replace all the mounting hardware for the 3 pin with all the internals and hardware with your original 4 pin parts?

 

No. Completly different throttle body

 

What is completely different, looking at photos it looks to me to be exactly the same as my throttle body the only difference I can see is a different TPS (3 pin) which I know hooks up differently than the 4 pin. I'm working with a 96 3.4 Tacoma and my throttle plate and throat is wore enough I can't get it to idle less than 1300rpm, the guy that used to bore them is not doing it anymore and trying to find a solution.