No computer change needed.
May need to swap CPS(cam position sensor) from '99 to '00 unless both are 2-wire.
They changed the 3-wire CPS to a 2-wire in the late '90's.
Change rear main seal on '00 before installing.
Check all the core plugs(freeze plugs) on the '00 while it is out, replace any that have any signs of rust.
If '99 is an automatic and this is your first time, you can ruin the trans if you don't have torque converter in the correct position when you bolt trans to block.
Last edited by RonD; 06-16-2015 at 08:51 AM.