Only way to make life easier is to have the donor car next to yours, too much has changed in 21 years especially with ECM's and wiring.

 

i have done the swap its very easy, u will use the original 2001 harness,

i even used the original 2001 harness, intake manifold, and exhaust manifold from original engine . The entire long block is the same. basically, doing is swapping the long block. Carry sensors, intake, exhaust, and belt drive accessories over from the old motor to the new one.


Only sensors carried over from old engine is the temp sensor on the driver's side of the head and the knock sensor (knock sensor of corolla 2003-2008 in the block is not the same (1 wire for 8th Gen vs. 2 wire for 9th Gen Corolla)


move the old fuel rail over use the metal coolant hose from the old engine that runs under the intake. And obviously move the intake manifold over as well and swap engine mount bracket