CA18DET is old has its ups and downs
RB20DET is old has its ups and downs
if ur stuck on a RB do a RB25DET newer and interchanging parts with other RB is greater, CA18DET's are cool too rev happy not as heavy as an RB and can make decent power, driving one i know its low bottom end but top end on a CA is where its at. i liked it. it depends what YOU wanna do.