You shouldn't any problems using any of the engines from 98-00. The late 99-00 have returnless fuel but that doesn't have anything to do with the actual long block itself.

-'96 SE MTX 3L -'98 SVT 1,173 of 6,535 -'05 Mazda 6s, loaded, g/f's ride -Need a 96-00 manual on CD? PM or email me