The Ca18DE for early Nissans are not reliable. The parts too are expensive. I rather swap a GA16DE with a growing aftermarket support, than an older engine that has none. Actually, I've been thinking of modding my engine now. Maybe mild port and polished, euro cam from Nismo, rebore the cylinder, stronger/lighter valves. Or even low PSI homemade turbo, just to psst off the Honda boys. There is one GA16i turbo that I know of and parts came from Ford Probe and Mazda MX6 with custom pipes. Here is a sample pic
