[chevy only please.]

Hey everybody! I have an Isuzu npr commercial truck that runs a l05 engine with an 480le(w/o mlps) transmission perfectly. However I would like to add more power and torque to the truck by adding an l31 motor. Im not sure how the current l05 works with the 480le because arnt the 480le trans electronically controlled?and i dont see a exterior tcm. and theres not one on the trans.

Anyways...

Can i just swap in a l31? Will it work with the older 480le without the mlps?. or do i need the newer 48ole with the attached mlps? and if i need the newer trans then im assuming i would need the wire harness, ecm and new lines to the transmission cooler. to go with it?

also there are 96 and up isuzu npr truck that run with an l31 stock. im just not sure what transmission they come with.

also would a lo5 wire harness work with an l31 motor?

thanks for any input at all!