can i just switch em and make sure all wires and cords are in place?
best thing to do is just do it. That's the fun part. Seein they both old P3 chips on the boards. you may not have a problem. How and where was the replacement board stored. If you had it in a safe place...cool. If not. and you had it in the open...like in a box of spare shit in the garage...some connections or circuits on the board could be scratched or damaged. Or could of been exposed to some static electricity. I never folllowed the rule myself and have damaged some otherwise good boards with careless storage and handling. Also, even though they have P3 chips on board...the mother board itself could be different manufactuers. Eventhough, Windows will load default/generic drivers to get the board running. Sometines...that doesn't always go as expected and you need to search for the MB drivers for your board.