'01 engines will work fine with a direct drop in minus the issues with the intake manifolds. Those have fairly straight forward workarounds though.
engines earlier than 00 all have a different water pump location and require an electric water pump or hybridizing the 2.5L heads so that the waterpump remains in the stock location.
Former owner of '99 CSVT - Silver #222/2760
356/334 wHP/TQ at 10psi on pump gas!
See My Mods
'05 Volvo S40 Turbo 5 AWD with 6spd, Passion Red
'06 Mazda5 Touring, 5spd,MTX, Black