The E16 engines and the CA16DE both came with the RS5F31A 5 speed cable clutch tranny. I do not know if the bell housing is the same exact shape for an E-series and a CA-series tranny, but if it is, then yes, you can put it on your CA18DE. The CA16DE and CA18DE blocks are exactly the same on the outside. I don't think the RS5F31A would be "too weak" for the CA18DE. It came with the CA16, and the CA18 technically isn't heaps stronger. USDM CA16DE = 113 HP, 99 ft. lbs. torque @ 4,800 RPMs, USDM CA18DE = 125 HP, 115 ft. lbs. torque @ 4,800? RPMs. I have seen a couple of other people on other forums post that they've done it with no problems, and a couple even tried it on the CA18DET!!! Oh yeah, even though both series came with the RS5F31A, the gears are slightly different. I believe the CA version has slightly shorter, more close ratio gears than the E-series one did.[/QUOTE]
Correct, I just finished swaping a CA18DE in place of the CA16DE. I used all the 1.6L stuff including the trans, clutch, and flywheel. I race it on a clay oval turning between 6,000 and 7,000 rpm. So far, so good.