I get tired of people suggesting dropping SR20s in every 4-cyl Nissan available. SR20s are not easy swaps for B-series chassis... it involves modifying the frame and firewall, as well as getting new CV axles and other parts that add up a bill quickly. You can pull well over 200 horsepower at the wheels from a GA series engine, you just have to know what to do. Performance camshafts, performance ECU, advanced timing, KA24 or CA20 fuel injectors, KA24 or CA20 fuel pump, port & polished cylinder head, headers, good exhaust system, Unorthodox crank pulley, performance flywheel, and a few other miscellaneous parts will give you around 200 horses. That is more than enough for a B-series chassis to make a great run in a quarter or eighth mile. All of those items cost less than it would to have a garage install an SR20 and purchase the stock engine itself. I have worked on SR20s, and they are great engines, but they are not the only good 4-cyl Nissan ever made. Both the GA series, CA series, and KA series are all good platforms. As for the performance ECU and cams fitting on your engine, just buy a GA16DE cylinder head and put it on your block. They are both GA series engines, so the cylinder head should fit without any complications. Your engine is already a twin cam, so timing should not be difficult, as well as MPFI, so you could probably use both your stock exhaust and intake manifolds. Then you can fit your cams... and the ECU, but you can always adjust the fuel regulator to reduce the richness.
